31130240 has 64 divisors (see below), whose sum is σ = 75202560. Its totient is φ = 12321792.

The previous prime is 31130233. The next prime is 31130243. The reversal of 31130240 is 4203113.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31130243) 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, 81089 + ... + 81471.

It is an arithmetic number, because the mean of its divisors is an integer number (1175040).

Almost surely, 2^31130240 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31130240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37601280).

31130240 is an abundant number, since it is smaller than the sum of its proper divisors (44072320).

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

31130240 is a wasteful number, since it uses less digits than its factorization.

31130240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 529 (or 517 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 31130240 is about 5579.4480013707. The cubic root of 31130240 is about 314.5773789886.

Adding to 31130240 its reverse (4203113), we get a palindrome (35333353).

The spelling of 31130240 in words is "thirty-one million, one hundred thirty thousand, two hundred forty".