77312656512 has 384 divisors, whose sum is σ = 276674885760. Its totient is φ = 20177289216.

The previous prime is 77312656493. The next prime is 77312656537. The reversal of 77312656512 is 21565621377.

It is a happy number.

77312656512 is a `hidden beast` number, since 7 + 7 + 3 + 126 + 5 + 6 + 512 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-2 number, since 2×77312656512² (a number of 23 digits) contains 22 as substring.

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, 10164903 + ... + 10172505.

It is an arithmetic number, because the mean of its divisors is an integer number (720507515).

Almost surely, 2^77312656512 is an apocalyptic number.

77312656512 is a gapful number since it is divisible by the number (72) 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 77312656512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138337442880).

77312656512 is an abundant number, since it is smaller than the sum of its proper divisors (199362229248).

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

77312656512 is a wasteful number, since it uses less digits than its factorization.

77312656512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7740 (or 7725 counting only the distinct ones).

The product of its digits is 529200, while the sum is 45.

The spelling of 77312656512 in words is "seventy-seven billion, three hundred twelve million, six hundred fifty-six thousand, five hundred twelve".