91561593600 has 648 divisors, whose sum is σ = 338978897712. Its totient is φ = 23563468800.

The previous prime is 91561593553. The next prime is 91561593601. The reversal of 91561593600 is 639516519.

91561593600 is a `hidden beast` number, since 9 + 1 + 56 + 1 + 593 + 6 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (91561593601) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 323539059 + ... + 323539341.

Almost surely, 2^91561593600 is an apocalyptic number.

91561593600 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91561593600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (169489448856).

91561593600 is an abundant number, since it is smaller than the sum of its proper divisors (247417304112).

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

91561593600 is a wasteful number, since it uses less digits than its factorization.

91561593600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 493 (or 471 counting only the distinct ones).

The product of its (nonzero) digits is 218700, while the sum is 45.

It can be divided in two parts, 9156 and 1593600, that added together give a square (1602756 = 1266²).

The spelling of 91561593600 in words is "ninety-one billion, five hundred sixty-one million, five hundred ninety-three thousand, six hundred".