91549591 has 12 divisors (see below), whose sum is σ = 111128112. Its totient is φ = 75058368.

The previous prime is 91549553. The next prime is 91549609. The reversal of 91549591 is 19594519.

It is not a de Polignac number, because 91549591 - 2⁷ = 91549463 is a prime.

It is a super-2 number, since 2×91549591² = 16762655224534562, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91549691) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39490 + ... + 41743.

It is an arithmetic number, because the mean of its divisors is an integer number (9260676).

Almost surely, 2^91549591 is an apocalyptic number.

91549591 is a deficient number, since it is larger than the sum of its proper divisors (19578521).

91549591 is a wasteful number, since it uses less digits than its factorization.

91549591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81270 (or 81263 counting only the distinct ones).

The product of its digits is 72900, while the sum is 43.

The square root of 91549591 is about 9568.1550468207. The cubic root of 91549591 is about 450.6978325109.

The spelling of 91549591 in words is "ninety-one million, five hundred forty-nine thousand, five hundred ninety-one".