31130388 has 18 divisors (see below), whose sum is σ = 78690794. Its totient is φ = 10376784.

The previous prime is 31130387. The next prime is 31130399. The reversal of 31130388 is 88303113.

It can be written as a sum of positive squares in only one way, i.e., 20903184 + 10227204 = 4572^2 + 3198^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31130381) 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, 432331 + ... + 432402.

Almost surely, 2^31130388 is an apocalyptic number.

It is an amenable number.

31130388 is an abundant number, since it is smaller than the sum of its proper divisors (47560406).

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

31130388 is a wasteful number, since it uses less digits than its factorization.

31130388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 864743 (or 864738 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 31130388 is about 5579.4612643158. The cubic root of 31130388 is about 314.5778775111.

The spelling of 31130388 in words is "thirty-one million, one hundred thirty thousand, three hundred eighty-eight".