<PAGE>
<TABLE>
<CAPTION>
<S> <C>
PROSPECTUS SUPPLEMENT FILE NO. 333-59997
(TO PROSPECTUS AND PROSPECTUS SUPPLEMENT DATED JULY 30, 1998) RULE 424(B)(3)
PROSPECTUS NUMBER: 1787
</TABLE>
MERRILL LYNCH & CO., INC.
MEDIUM-TERM NOTES, SERIES B
DUE NINE MONTHS OR MORE FROM DATE OF ISSUE
FLOATING RATE NOTES
<TABLE>
<CAPTION>
<S> <C> <C> <C>
PRINCIPAL AMOUNT: $25,000,000 ORIGINAL ISSUE October 28,
DATE: 1998
CUSIP NUMBER: 59018S S62 STATED MATURITY October 28,
DATE: 1999
INTEREST CALCULATION: DAY COUNT CONVENTION:
/x/ REGULAR FLOATING RATE NOTE /x/ ACTUAL/360
/ / INVERSE FLOATING RATE NOTE / / 30/360
(FIXED INTEREST RATE): / / ACTUAL/ACTUAL
INTEREST RATE BASIS:
/ / LIBOR / / COMMERCIAL PAPER RATE
/ / CMT RATE / / ELEVENTH DISTRICT COST OF
/ / PRIME RATE FUNDS RATE
/x/ FEDERAL FUNDS RATE / / CD RATE
/ / TREASURY RATE / / OTHER (SEE ATTACHED)
DESIGNATED CMT PAGE:
CMT TELERATE PAGE: DESIGNATED LIBOR PAGE:
CMT REUTERS PAGE: LIBOR TELERATE PAGE:
LIBOR REUTERS PAGE:
INDEX MATURITY: Daily MINIMUM INTEREST Not Applicable
RATE:
SPREAD: 0.210% MAXIMUM INTEREST Not Applicable
RATE:
INITIAL INTEREST RATE: TBD, based on the daily opening Federal Funds Rate. SPREAD MULTIPLIER: Not Applicable
INTEREST RESET DATES: Daily, commencing October 28, 1998 through maturity date, subject to following
business day convention.
INTEREST PAYMENT DATES: Quarterly, on the 28th of January, April, July and October; subject to
following business day convention.
REPAYMENT AT THE
OPTION OF THE HOLDER: The Notes cannot be repaid prior to the Stated Maturity Date.
REDEMPTION AT THE
OPTION OF THE COMPANY: The Notes cannot be redeemed prior to the Stated Maturity Date.
FORM: The Notes are being issued in fully registered book-entry form.
TRUSTEE: The Chase Manhattan Bank
DATED: October 26, 1998
</TABLE>