31313320 has 32 divisors (see below), whose sum is σ = 74601000. Its totient is φ = 11788288.

The previous prime is 31313297. The next prime is 31313351. The reversal of 31313320 is 2331313.

It can be written as a sum of positive squares in 4 ways, for example, as 19766916 + 11546404 = 4446^2 + 3398^2 .

It is a junction number, because it is equal to n+sod(n) for n = 31313294 and 31313303.

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, 22345 + ... + 23704.

Almost surely, 2^31313320 is an apocalyptic number.

It is an amenable number.

31313320 is an abundant number, since it is smaller than the sum of its proper divisors (43287680).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31313320 is a wasteful number, since it uses less digits than its factorization.

31313320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46077 (or 46073 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 16.

The square root of 31313320 is about 5595.8305907166. The cubic root of 31313320 is about 315.1928608156.

Adding to 31313320 its reverse (2331313), we get a palindrome (33644633).

The spelling of 31313320 in words is "thirty-one million, three hundred thirteen thousand, three hundred twenty".