91616553840 has 80 divisors (see below), whose sum is σ = 324584368128. Its totient is φ = 20940926208.

The previous prime is 91616553823. The next prime is 91616553841. The reversal of 91616553840 is 4835561619.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 91616553840.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91616553841) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27265152 + ... + 27268511.

Almost surely, 2^91616553840 is an apocalyptic number.

It is an amenable number.

91616553840 is an abundant number, since it is smaller than the sum of its proper divisors (232967814288).

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

91616553840 is a wasteful number, since it uses less digits than its factorization.

91616553840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54533686 (or 54533680 counting only the distinct ones).

The product of its (nonzero) digits is 777600, while the sum is 48.

The spelling of 91616553840 in words is "ninety-one billion, six hundred sixteen million, five hundred fifty-three thousand, eight hundred forty".