31604531 has 8 divisors (see below), whose sum is σ = 37284864. Its totient is φ = 26215560.

The previous prime is 31604509. The next prime is 31604533. The reversal of 31604531 is 13540613.

It is a happy number.

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

It is a de Polignac number, because none of the positive numbers 2^k-31604531 is a prime.

It is a super-2 number, since 2×31604531² = 1997692759459922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31604497 and 31604506.

It is not an unprimeable number, because it can be changed into a prime (31604533) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72605 + ... + 73038.

It is an arithmetic number, because the mean of its divisors is an integer number (4660608).

Almost surely, 2^31604531 is an apocalyptic number.

31604531 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

31604531 is a deficient number, since it is larger than the sum of its proper divisors (5680333).

31604531 is a wasteful number, since it uses less digits than its factorization.

31604531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145681.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 31604531 is about 5621.7907289404. The cubic root of 31604531 is about 316.1669356438.

The spelling of 31604531 in words is "thirty-one million, six hundred four thousand, five hundred thirty-one".