31161372 has 48 divisors (see below), whose sum is σ = 80016384. Its totient is φ = 9438000.

The previous prime is 31161367. The next prime is 31161373. The reversal of 31161372 is 27316113.

It is a super-2 number, since 2×31161372² = 1942062209844768, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31161373) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14997 + ... + 16947.

It is an arithmetic number, because the mean of its divisors is an integer number (1667008).

Almost surely, 2^31161372 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 31161372, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40008192).

31161372 is an abundant number, since it is smaller than the sum of its proper divisors (48855012).

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

31161372 is a wasteful number, since it uses less digits than its factorization.

31161372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1991 (or 1967 counting only the distinct ones).

The product of its digits is 756, while the sum is 24.

The square root of 31161372 is about 5582.2371859318. The cubic root of 31161372 is about 314.6822091057.

Adding to 31161372 its reverse (27316113), we get a palindrome (58477485).

The spelling of 31161372 in words is "thirty-one million, one hundred sixty-one thousand, three hundred seventy-two".