78130931 has 4 divisors (see below), whose sum is σ = 81527952. Its totient is φ = 74733912.

The previous prime is 78130891. The next prime is 78130933. The reversal of 78130931 is 13903187.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13903187 = 3191 ⋅4357.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78130931 is a prime.

It is a super-2 number, since 2×78130931² = 12208884757853522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78130933) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1698476 + ... + 1698521.

It is an arithmetic number, because the mean of its divisors is an integer number (20381988).

Almost surely, 2^78130931 is an apocalyptic number.

78130931 is a deficient number, since it is larger than the sum of its proper divisors (3397021).

78130931 is a wasteful number, since it uses less digits than its factorization.

78130931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3397020.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 78130931 is about 8839.1702664899. The cubic root of 78130931 is about 427.5048043873.

The spelling of 78130931 in words is "seventy-eight million, one hundred thirty thousand, nine hundred thirty-one".