31131400 has 24 divisors (see below), whose sum is σ = 72380970. Its totient is φ = 12452480.

The previous prime is 31131379. The next prime is 31131407. The reversal of 31131400 is 413113.

It can be written as a sum of positive squares in 3 ways, for example, as 20412324 + 10719076 = 4518^2 + 3274^2 .

It is not an unprimeable number, because it can be changed into a prime (31131407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 77629 + ... + 78028.

Almost surely, 2^31131400 is an apocalyptic number.

It is an amenable number.

31131400 is an abundant number, since it is smaller than the sum of its proper divisors (41249570).

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

31131400 is a wasteful number, since it uses less digits than its factorization.

31131400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155673 (or 155664 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 31131400 is about 5579.5519533382. The cubic root of 31131400 is about 314.5812862850.

Adding to 31131400 its reverse (413113), we get a palindrome (31544513).

The spelling of 31131400 in words is "thirty-one million, one hundred thirty-one thousand, four hundred".