77915930 has 24 divisors (see below), whose sum is σ = 148718268. Its totient is φ = 29289728.

The previous prime is 77915923. The next prime is 77915933. The reversal of 77915930 is 3951977.

It is a Cunningham number, because it is equal to 8827²+1.

It can be written as a sum of positive squares in 6 ways, for example, as 77915929 + 1 = 8827^2 + 1^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (77915933) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 114752 + ... + 115428.

Almost surely, 2^77915930 is an apocalyptic number.

77915930 is a deficient number, since it is larger than the sum of its proper divisors (70802338).

77915930 is an equidigital number, since it uses as much as digits as its factorization.

77915930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1378 (or 701 counting only the distinct ones).

The product of its (nonzero) digits is 59535, while the sum is 41.

The square root of 77915930 is about 8827.0000566444. Note that the first 4 decimals coincide. The cubic root of 77915930 is about 427.1123076806.

The spelling of 77915930 in words is "seventy-seven million, nine hundred fifteen thousand, nine hundred thirty".