31221304 has 16 divisors (see below), whose sum is σ = 61085520. Its totient is φ = 14931840.

The previous prime is 31221283. The next prime is 31221317. The reversal of 31221304 is 40312213.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 84657 + ... + 85024.

It is an arithmetic number, because the mean of its divisors is an integer number (3817845).

Almost surely, 2^31221304 is an apocalyptic number.

It is an amenable number.

31221304 is a deficient number, since it is larger than the sum of its proper divisors (29864216).

31221304 is a wasteful number, since it uses less digits than its factorization.

31221304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169710 (or 169706 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 31221304 is about 5587.6027059912. The cubic root of 31221304 is about 314.8838204292.

Adding to 31221304 its reverse (40312213), we get a palindrome (71533517).

Subtracting 31221304 from its reverse (40312213), we obtain a palindrome (9090909).

The spelling of 31221304 in words is "thirty-one million, two hundred twenty-one thousand, three hundred four".