56991781440 has 336 divisors, whose sum is σ = 221772358080. Its totient is φ = 13815982080.

The previous prime is 56991781421. The next prime is 56991781459. The reversal of 56991781440 is 4418719965.

56991781440 is a `hidden beast` number, since 569 + 9 + 1 + 78 + 1 + 4 + 4 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (56991781421) and next prime (56991781459).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 822046 + ... + 888674.

It is an arithmetic number, because the mean of its divisors is an integer number (660036780).

Almost surely, 2^56991781440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 56991781440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110886179040).

56991781440 is an abundant number, since it is smaller than the sum of its proper divisors (164780576640).

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

56991781440 is a wasteful number, since it uses less digits than its factorization.

56991781440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66672 (or 66650 counting only the distinct ones).

The product of its (nonzero) digits is 2177280, while the sum is 54.

The spelling of 56991781440 in words is "fifty-six billion, nine hundred ninety-one million, seven hundred eighty-one thousand, four hundred forty".