<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
SEMI-ANNUAL REPORT OF AMERICAN CENTURY MUTUAL FUNDS, INC. AND IS QUALIFIED
IN ITS ENTIRETY BY REFERENCE TO SUCH REPORT.
</LEGEND>
<CIK> 0000100334
<NAME> AMERICAN CENTURY MUTUAL FUNDS, INC.
<SERIES>
<NUMBER> 11
<NAME> GROWTH FUND - INVESTOR CLASS
<MULTIPLIER> 1000
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> OCT-31-2000
<PERIOD-END> APR-30-2000
<INVESTMENTS-AT-COST> 7,086,805
<INVESTMENTS-AT-VALUE> 10,409,381
<RECEIVABLES> 93,024
<ASSETS-OTHER> 707
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 10,503,112
<PAYABLE-FOR-SECURITIES> 220,647
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 8,397
<TOTAL-LIABILITIES> 229,044
<SENIOR-EQUITY> 3,028
<PAID-IN-CAPITAL-COMMON> 6,167,764
<SHARES-COMMON-STOCK> 302,786
<SHARES-COMMON-PRIOR> 263,727
<ACCUMULATED-NII-CURRENT> (16,030)
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 788,971
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 3,330,335
<NET-ASSETS> 10,274,068
<DIVIDEND-INCOME> 21,239
<INTEREST-INCOME> 11,344
<OTHER-INCOME> 0
<EXPENSES-NET> 48,703
<NET-INVESTMENT-INCOME> (16,120)
<REALIZED-GAINS-CURRENT> 818,543
<APPREC-INCREASE-CURRENT> 950,546
<NET-CHANGE-FROM-OPS> 1,752,969
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> 10,954,947
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 38,370
<NUMBER-OF-SHARES-REDEEMED> (33,450)
<SHARES-REINVESTED> 34,139
<NET-CHANGE-IN-ASSETS> 1,927,226
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 1,068,029
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 48,634
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 48,703
<AVERAGE-NET-ASSETS> 9,932,851
<PER-SHARE-NAV-BEGIN> 31.60
<PER-SHARE-NII> (0.06)
<PER-SHARE-GAIN-APPREC> 6.34
<PER-SHARE-DIVIDEND> 0.00
<PER-SHARE-DISTRIBUTIONS> 4.14
<RETURNS-OF-CAPITAL> 0.00
<PER-SHARE-NAV-END> 33.74
<EXPENSE-RATIO> 1.00
</TABLE>
