78906931 has 4 divisors (see below), whose sum is σ = 79483032. Its totient is φ = 78330832.

The previous prime is 78906929. The next prime is 78907007. The reversal of 78906931 is 13960987.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 78906931 - 2¹ = 78906929 is a prime.

It is a super-2 number, since 2×78906931² = 12452607519677522, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (78906131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 287845 + ... + 288118.

It is an arithmetic number, because the mean of its divisors is an integer number (19870758).

Almost surely, 2^78906931 is an apocalyptic number.

78906931 is a deficient number, since it is larger than the sum of its proper divisors (576101).

78906931 is a wasteful number, since it uses less digits than its factorization.

78906931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 576100.

The product of its (nonzero) digits is 81648, while the sum is 43.

The square root of 78906931 is about 8882.9573341315. The cubic root of 78906931 is about 428.9154768160.

The spelling of 78906931 in words is "seventy-eight million, nine hundred six thousand, nine hundred thirty-one".