31990431 has 8 divisors (see below), whose sum is σ = 46531584. Its totient is φ = 19388120.

The previous prime is 31990421. The next prime is 31990487. The reversal of 31990431 is 13409913.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31990431 - 2⁶ = 31990367 is a prime.

It is a super-2 number, since 2×31990431² = 2046775351131522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31990421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 484671 + ... + 484736.

It is an arithmetic number, because the mean of its divisors is an integer number (5816448).

Almost surely, 2^31990431 is an apocalyptic number.

31990431 is a deficient number, since it is larger than the sum of its proper divisors (14541153).

31990431 is a wasteful number, since it uses less digits than its factorization.

31990431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 969421.

The product of its (nonzero) digits is 2916, while the sum is 30.

The square root of 31990431 is about 5656.0083981550. The cubic root of 31990431 is about 317.4485617374.

The spelling of 31990431 in words is "thirty-one million, nine hundred ninety thousand, four hundred thirty-one".