78765931 has 2 divisors, whose sum is σ = 78765932. Its totient is φ = 78765930.

The previous prime is 78765889. The next prime is 78765959. The reversal of 78765931 is 13956787.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78765931 - 2⁹ = 78765419 is a prime.

It is a super-2 number, since 2×78765931² = 12408143772593522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78765031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39382965 + 39382966.

It is an arithmetic number, because the mean of its divisors is an integer number (39382966).

Almost surely, 2^78765931 is an apocalyptic number.

78765931 is a deficient number, since it is larger than the sum of its proper divisors (1).

78765931 is an equidigital number, since it uses as much as digits as its factorization.

78765931 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 317520, while the sum is 46.

The square root of 78765931 is about 8875.0172394199. The cubic root of 78765931 is about 428.6598459534.

The spelling of 78765931 in words is "seventy-eight million, seven hundred sixty-five thousand, nine hundred thirty-one".