91863253440 has 672 divisors, whose sum is σ = 379918715904. Its totient is φ = 20692869120.

The previous prime is 91863253423. The next prime is 91863253483. The reversal of 91863253440 is 4435236819.

91863253440 is a `hidden beast` number, since 9 + 1 + 8 + 632 + 5 + 3 + 4 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 38645532 + ... + 38647908.

It is an arithmetic number, because the mean of its divisors is an integer number (565355232).

Almost surely, 2^91863253440 is an apocalyptic number.

91863253440 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 91863253440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (189959357952).

91863253440 is an abundant number, since it is smaller than the sum of its proper divisors (288055462464).

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

91863253440 is a wasteful number, since it uses less digits than its factorization.

91863253440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2487 (or 2465 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The spelling of 91863253440 in words is "ninety-one billion, eight hundred sixty-three million, two hundred fifty-three thousand, four hundred forty".