771615961 has 2 divisors, whose sum is σ = 771615962. Its totient is φ = 771615960.

The previous prime is 771615953. The next prime is 771615979. The reversal of 771615961 is 169516177.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 766182400 + 5433561 = 27680^2 + 2331^2 .

It is an emirp because it is prime and its reverse (169516177) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 771615961 - 2³ = 771615953 is a prime.

It is not a weakly prime, because it can be changed into another prime (771615931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 385807980 + 385807981.

It is an arithmetic number, because the mean of its divisors is an integer number (385807981).

Almost surely, 2^771615961 is an apocalyptic number.

It is an amenable number.

771615961 is a deficient number, since it is larger than the sum of its proper divisors (1).

771615961 is an equidigital number, since it uses as much as digits as its factorization.

771615961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 79380, while the sum is 43.

The square root of 771615961 is about 27777.9761861803. The cubic root of 771615961 is about 917.2063811107.

The spelling of 771615961 in words is "seven hundred seventy-one million, six hundred fifteen thousand, nine hundred sixty-one".