31155940 has 12 divisors (see below), whose sum is σ = 65427516. Its totient is φ = 12462368.

The previous prime is 31155937. The next prime is 31155967. The reversal of 31155940 is 4955113.

It can be written as a sum of positive squares in 2 ways, for example, as 20358144 + 10797796 = 4512^2 + 3286^2 .

It is a junction number, because it is equal to n+sod(n) for n = 31155899 and 31155908.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 778879 + ... + 778918.

It is an arithmetic number, because the mean of its divisors is an integer number (5452293).

Almost surely, 2^31155940 is an apocalyptic number.

It is an amenable number.

31155940 is an abundant number, since it is smaller than the sum of its proper divisors (34271576).

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

31155940 is a wasteful number, since it uses less digits than its factorization.

31155940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1557806 (or 1557804 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 28.

The square root of 31155940 is about 5581.7506214449. The cubic root of 31155940 is about 314.6639230785.

The spelling of 31155940 in words is "thirty-one million, one hundred fifty-five thousand, nine hundred forty".