31157980 has 24 divisors (see below), whose sum is σ = 74779488. Its totient is φ = 10682688.

The previous prime is 31157953. The next prime is 31157981. The reversal of 31157980 is 8975113.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31157981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 111139 + ... + 111418.

It is an arithmetic number, because the mean of its divisors is an integer number (3115812).

Almost surely, 2^31157980 is an apocalyptic number.

It is an amenable number.

31157980 is an abundant number, since it is smaller than the sum of its proper divisors (43621508).

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

31157980 is a wasteful number, since it uses less digits than its factorization.

31157980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222573 (or 222571 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 34.

The square root of 31157980 is about 5581.9333568218. The cubic root of 31157980 is about 314.6707906870.

The spelling of 31157980 in words is "thirty-one million, one hundred fifty-seven thousand, nine hundred eighty".