31172140 has 24 divisors (see below), whose sum is σ = 65938320. Its totient is φ = 12378048.

The previous prime is 31172137. The next prime is 31172149. The reversal of 31172140 is 4127113.

It is not an unprimeable number, because it can be changed into a prime (31172149) 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, 2827 + ... + 8386.

It is an arithmetic number, because the mean of its divisors is an integer number (2747430).

Almost surely, 2^31172140 is an apocalyptic number.

It is an amenable number.

31172140 is an abundant number, since it is smaller than the sum of its proper divisors (34766180).

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

31172140 is a wasteful number, since it uses less digits than its factorization.

31172140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11361 (or 11359 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 19.

The square root of 31172140 is about 5583.2015904855. The cubic root of 31172140 is about 314.7184517097.

Adding to 31172140 its reverse (4127113), we get a palindrome (35299253).

The spelling of 31172140 in words is "thirty-one million, one hundred seventy-two thousand, one hundred forty".