91123718400 has 1944 divisors, whose sum is σ = 412432727616. Its totient is φ = 18977587200.

The previous prime is 91123718353. The next prime is 91123718407. The reversal of 91123718400 is 481732119.

It is a happy number.

91123718400 is a `hidden beast` number, since 9 + 1 + 1 + 237 + 18 + 400 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (91123718407) by changing a digit.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 2462803182 + ... + 2462803218.

Almost surely, 2^91123718400 is an apocalyptic number.

91123718400 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 91123718400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (206216363808).

91123718400 is an abundant number, since it is smaller than the sum of its proper divisors (321309009216).

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

91123718400 is a wasteful number, since it uses less digits than its factorization.

91123718400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129 (or 94 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The spelling of 91123718400 in words is "ninety-one billion, one hundred twenty-three million, seven hundred eighteen thousand, four hundred".