77831518464 has 720 divisors, whose sum is σ = 280168627200. Its totient is φ = 21459271680.

The previous prime is 77831518441. The next prime is 77831518469. The reversal of 77831518464 is 46481513877.

77831518464 is a `hidden beast` number, since 7 + 7 + 83 + 1 + 518 + 46 + 4 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 77831518464.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77831518469) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 220485712 + ... + 220486064.

Almost surely, 2^77831518464 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 77831518464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (140084313600).

77831518464 is an abundant number, since it is smaller than the sum of its proper divisors (202337108736).

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

77831518464 is an equidigital number, since it uses as much as digits as its factorization.

77831518464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433 (or 396 counting only the distinct ones).

The product of its digits is 4515840, while the sum is 54.

The spelling of 77831518464 in words is "seventy-seven billion, eight hundred thirty-one million, five hundred eighteen thousand, four hundred sixty-four".