91009557640 has 32 divisors (see below), whose sum is σ = 204786636480. Its totient is φ = 36401132992.

The previous prime is 91009557607. The next prime is 91009557689. The reversal of 91009557640 is 4675590019.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 517077 + ... + 670363.

It is an arithmetic number, because the mean of its divisors is an integer number (6399582390).

Almost surely, 2^91009557640 is an apocalyptic number.

It is an amenable number.

91009557640 is an abundant number, since it is smaller than the sum of its proper divisors (113777078840).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91009557640 is a wasteful number, since it uses less digits than its factorization.

91009557640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168141 (or 168137 counting only the distinct ones).

The product of its (nonzero) digits is 340200, while the sum is 46.

The spelling of 91009557640 in words is "ninety-one billion, nine million, five hundred fifty-seven thousand, six hundred forty".