31313128 has 32 divisors (see below), whose sum is σ = 73200960. Its totient is φ = 12199680.

The previous prime is 31313123. The next prime is 31313141. The reversal of 31313128 is 82131313.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 31313099 and 31313108.

It is not an unprimeable number, because it can be changed into a prime (31313123) 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, 24801 + ... + 26032.

It is an arithmetic number, because the mean of its divisors is an integer number (2287530).

Almost surely, 2^31313128 is an apocalyptic number.

It is an amenable number.

31313128 is an abundant number, since it is smaller than the sum of its proper divisors (41887832).

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

31313128 is a wasteful number, since it uses less digits than its factorization.

31313128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50857 (or 50853 counting only the distinct ones).

The product of its digits is 432, while the sum is 22.

The square root of 31313128 is about 5595.8134350602. The cubic root of 31313128 is about 315.1922166046.

It can be divided in two parts, 3 and 1313128, that added together give a palindrome (1313131).

The spelling of 31313128 in words is "thirty-one million, three hundred thirteen thousand, one hundred twenty-eight".