77766961 has 2 divisors, whose sum is σ = 77766962. Its totient is φ = 77766960.

The previous prime is 77766947. The next prime is 77766977. The reversal of 77766961 is 16966777.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64400625 + 13366336 = 8025^2 + 3656^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77766961 is a prime.

It is not a weakly prime, because it can be changed into another prime (77766911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38883480 + 38883481.

It is an arithmetic number, because the mean of its divisors is an integer number (38883481).

Almost surely, 2^77766961 is an apocalyptic number.

It is an amenable number.

77766961 is a deficient number, since it is larger than the sum of its proper divisors (1).

77766961 is an equidigital number, since it uses as much as digits as its factorization.

77766961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 666792, while the sum is 49.

The square root of 77766961 is about 8818.5577619019. The cubic root of 77766961 is about 426.8399325447.

The spelling of 77766961 in words is "seventy-seven million, seven hundred sixty-six thousand, nine hundred sixty-one".