77657977640 has 32 divisors (see below), whose sum is σ = 178793952480. Its totient is φ = 30340790592.

The previous prime is 77657977637. The next prime is 77657977651. The reversal of 77657977640 is 4677975677.

It is a super-2 number, since 2×77657977640² (a number of 23 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (65) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22573274 + ... + 22576713.

It is an arithmetic number, because the mean of its divisors is an integer number (5587311015).

Almost surely, 2^77657977640 is an apocalyptic number.

It is an amenable number.

77657977640 is an abundant number, since it is smaller than the sum of its proper divisors (101135974840).

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

77657977640 is a wasteful number, since it uses less digits than its factorization.

77657977640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45150041 (or 45150037 counting only the distinct ones).

The product of its (nonzero) digits is 108909360, while the sum is 65.

The spelling of 77657977640 in words is "seventy-seven billion, six hundred fifty-seven million, nine hundred seventy-seven thousand, six hundred forty".