78490931 has 2 divisors, whose sum is σ = 78490932. Its totient is φ = 78490930.

The previous prime is 78490913. The next prime is 78490939. The reversal of 78490931 is 13909487.

It is a happy number.

Together with previous prime (78490913) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78490931 - 2²⁶ = 11382067 is a prime.

It is a super-2 number, since 2×78490931² = 12321652498493522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78490939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39245465 + 39245466.

It is an arithmetic number, because the mean of its divisors is an integer number (39245466).

Almost surely, 2^78490931 is an apocalyptic number.

78490931 is a deficient number, since it is larger than the sum of its proper divisors (1).

78490931 is an equidigital number, since it uses as much as digits as its factorization.

78490931 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54432, while the sum is 41.

The square root of 78490931 is about 8859.5107652737. The cubic root of 78490931 is about 428.1603960363.

The spelling of 78490931 in words is "seventy-eight million, four hundred ninety thousand, nine hundred thirty-one".