31081604 has 24 divisors (see below), whose sum is σ = 56060928. Its totient is φ = 15069600.

The previous prime is 31081577. The next prime is 31081619. The reversal of 31081604 is 40618013.

It is a super-2 number, since 2×31081604² = 1932132214425632, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31081604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26429 + ... + 27579.

It is an arithmetic number, because the mean of its divisors is an integer number (2335872).

Almost surely, 2^31081604 is an apocalyptic number.

It is an amenable number.

31081604 is a deficient number, since it is larger than the sum of its proper divisors (24979324).

31081604 is a wasteful number, since it uses less digits than its factorization.

31081604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1355 (or 1353 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 31081604 is about 5575.0878019992. The cubic root of 31081604 is about 314.4134680546.

Adding to 31081604 its reverse (40618013), we get a palindrome (71699617).

The spelling of 31081604 in words is "thirty-one million, eighty-one thousand, six hundred four".