31813980 has 192 divisors, whose sum is σ = 106444800. Its totient is φ = 7015680.

The previous prime is 31813979. The next prime is 31813981. The reversal of 31813980 is 8931813.

It is an interprime number because it is at equal distance from previous prime (31813979) and next prime (31813981).

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31813981) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 539191 + ... + 539249.

It is an arithmetic number, because the mean of its divisors is an integer number (554400).

Almost surely, 2^31813980 is an apocalyptic number.

31813980 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31813980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (53222400).

31813980 is an abundant number, since it is smaller than the sum of its proper divisors (74630820).

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

31813980 is a wasteful number, since it uses less digits than its factorization.

31813980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144 (or 142 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 31813980 is about 5640.3882845067. The cubic root of 31813980 is about 316.8638304323.

The spelling of 31813980 in words is "thirty-one million, eight hundred thirteen thousand, nine hundred eighty".