978931331 has 4 divisors (see below), whose sum is σ = 1118778672. Its totient is φ = 839083992.

The previous prime is 978931321. The next prime is 978931379. The reversal of 978931331 is 133139879.

978931331 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 133139879 = 2609 ⋅51031.

It is a cyclic number.

It is not a de Polignac number, because 978931331 - 2¹⁴ = 978914947 is a prime.

It is a super-2 number, since 2×978931331² = 1916613101626863122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (978931301) 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, 69923660 + ... + 69923673.

It is an arithmetic number, because the mean of its divisors is an integer number (279694668).

Almost surely, 2^978931331 is an apocalyptic number.

978931331 is a deficient number, since it is larger than the sum of its proper divisors (139847341).

978931331 is a wasteful number, since it uses less digits than its factorization.

978931331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139847340.

The product of its digits is 122472, while the sum is 44.

The square root of 978931331 is about 31287.8783397021. The cubic root of 978931331 is about 992.9272038252.

The spelling of 978931331 in words is "nine hundred seventy-eight million, nine hundred thirty-one thousand, three hundred thirty-one".