31307172 has 48 divisors (see below), whose sum is σ = 79488192. Its totient is φ = 9532800.

The previous prime is 31307167. The next prime is 31307191. The reversal of 31307172 is 27170313.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14763 + ... + 16749.

It is an arithmetic number, because the mean of its divisors is an integer number (1656004).

Almost surely, 2^31307172 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 31307172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39744096).

31307172 is an abundant number, since it is smaller than the sum of its proper divisors (48181020).

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

31307172 is a wasteful number, since it uses less digits than its factorization.

31307172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2108 (or 2106 counting only the distinct ones).

The product of its (nonzero) digits is 882, while the sum is 24.

The square root of 31307172 is about 5595.2812261762. The cubic root of 31307172 is about 315.1722313354.

Adding to 31307172 its reverse (27170313), we get a palindrome (58477485).

The spelling of 31307172 in words is "thirty-one million, three hundred seven thousand, one hundred seventy-two".