77939161 has 2 divisors, whose sum is σ = 77939162. Its totient is φ = 77939160.

The previous prime is 77939149. The next prime is 77939167. The reversal of 77939161 is 16193977.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41409225 + 36529936 = 6435^2 + 6044^2 .

It is a cyclic number.

It is not a de Polignac number, because 77939161 - 2²¹ = 75842009 is a prime.

It is not a weakly prime, because it can be changed into another prime (77939167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38969580 + 38969581.

It is an arithmetic number, because the mean of its divisors is an integer number (38969581).

Almost surely, 2^77939161 is an apocalyptic number.

It is an amenable number.

77939161 is a deficient number, since it is larger than the sum of its proper divisors (1).

77939161 is an equidigital number, since it uses as much as digits as its factorization.

77939161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 71442, while the sum is 43.

The square root of 77939161 is about 8828.3158643084. The cubic root of 77939161 is about 427.1547519752.

The spelling of 77939161 in words is "seventy-seven million, nine hundred thirty-nine thousand, one hundred sixty-one".