331931961 has 9 divisors (see below), whose sum is σ = 479536239. Its totient is φ = 221251536.

The previous prime is 331931959. The next prime is 331931989. The reversal of 331931961 is 169139133.

The square root of 331931961 is 18219.

It is a perfect power (a square), and thus also a powerful number.

331931961 is a `hidden beast` number, since 331 + 9 + 319 + 6 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 301196025 + 30735936 = 17355^2 + 5544^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 331931961 - 2¹ = 331931959 is a prime.

It is a super-2 number, since 2×331931961² = 220357653466611042, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (331531961) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 51621 + ... + 57693.

Almost surely, 2^331931961 is an apocalyptic number.

331931961 is the 18219-th square number.

331931961 is the 9110-th centered octagonal number.

It is an amenable number.

331931961 is a deficient number, since it is larger than the sum of its proper divisors (147604278).

331931961 is an frugal number, since it uses more digits than its factorization.

331931961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12152 (or 6076 counting only the distinct ones).

The product of its digits is 13122, while the sum is 36.

The cubic root of 331931961 is about 692.3882522008.

Multiplying 331931961 by its sum of digits (36), we get a square (11949550596 = 109314²).

The spelling of 331931961 in words is "three hundred thirty-one million, nine hundred thirty-one thousand, nine hundred sixty-one".