31328031 has 16 divisors (see below), whose sum is σ = 48029184. Its totient is φ = 17792544.

The previous prime is 31328027. The next prime is 31328039. The reversal of 31328031 is 13082313.

It is a happy number.

It is not a de Polignac number, because 31328031 - 2² = 31328027 is a prime.

It is a super-2 number, since 2×31328031² = 1962891052673922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 31327989 and 31328007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31328039) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 960 + ... + 7973.

It is an arithmetic number, because the mean of its divisors is an integer number (3001824).

Almost surely, 2^31328031 is an apocalyptic number.

31328031 is a deficient number, since it is larger than the sum of its proper divisors (16701153).

31328031 is a wasteful number, since it uses less digits than its factorization.

31328031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9110.

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 31328031 is about 5597.1448971775. The cubic root of 31328031 is about 315.2422122975.

The spelling of 31328031 in words is "thirty-one million, three hundred twenty-eight thousand, thirty-one".