31315988 has 12 divisors (see below), whose sum is σ = 59785152. Its totient is φ = 14234520.

The previous prime is 31315981. The next prime is 31315993. The reversal of 31315988 is 88951313.

It is a super-2 number, since 2×31315988² = 1961382208832288, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31315981) by changing a digit.

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, 355820 + ... + 355907.

It is an arithmetic number, because the mean of its divisors is an integer number (4982096).

Almost surely, 2^31315988 is an apocalyptic number.

It is an amenable number.

31315988 is a deficient number, since it is larger than the sum of its proper divisors (28469164).

31315988 is a wasteful number, since it uses less digits than its factorization.

31315988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 711742 (or 711740 counting only the distinct ones).

The product of its digits is 25920, while the sum is 38.

The square root of 31315988 is about 5596.0689774162. The cubic root of 31315988 is about 315.2018123913.

It can be divided in two parts, 3131 and 5988, that added together give a palindrome (9119).

The spelling of 31315988 in words is "thirty-one million, three hundred fifteen thousand, nine hundred eighty-eight".