78903931 has 2 divisors, whose sum is σ = 78903932. Its totient is φ = 78903930.

The previous prime is 78903893. The next prime is 78903947. The reversal of 78903931 is 13930987.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78903931 is a prime.

It is a super-2 number, since 2×78903931² = 12451660654505522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78903991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39451965 + 39451966.

It is an arithmetic number, because the mean of its divisors is an integer number (39451966).

Almost surely, 2^78903931 is an apocalyptic number.

78903931 is a deficient number, since it is larger than the sum of its proper divisors (1).

78903931 is an equidigital number, since it uses as much as digits as its factorization.

78903931 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40824, while the sum is 40.

The square root of 78903931 is about 8882.7884698444. The cubic root of 78903931 is about 428.9100410335.

The spelling of 78903931 in words is "seventy-eight million, nine hundred three thousand, nine hundred thirty-one".