77691556 has 12 divisors (see below), whose sum is σ = 139276620. Its totient is φ = 37898240.

The previous prime is 77691529. The next prime is 77691557. The reversal of 77691556 is 65519677.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1478656 + 76212900 = 1216^2 + 8730^2 .

It is a super-2 number, since 2×77691556² = 12071955747402272, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (77691557) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 236701 + ... + 237028.

It is an arithmetic number, because the mean of its divisors is an integer number (11606385).

Almost surely, 2^77691556 is an apocalyptic number.

It is an amenable number.

77691556 is a deficient number, since it is larger than the sum of its proper divisors (61585064).

77691556 is a wasteful number, since it uses less digits than its factorization.

77691556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 473774 (or 473772 counting only the distinct ones).

The product of its digits is 396900, while the sum is 46.

The square root of 77691556 is about 8814.2813660559. The cubic root of 77691556 is about 426.7019293230.

The spelling of 77691556 in words is "seventy-seven million, six hundred ninety-one thousand, five hundred fifty-six".