31620940 has 96 divisors (see below), whose sum is σ = 77757120. Its totient is φ = 10699776.

The previous prime is 31620937. The next prime is 31620943. The reversal of 31620940 is 4902613.

It is an interprime number because it is at equal distance from previous prime (31620937) and next prime (31620943).

It is not an unprimeable number, because it can be changed into a prime (31620943) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 182694 + ... + 182866.

It is an arithmetic number, because the mean of its divisors is an integer number (809970).

Almost surely, 2^31620940 is an apocalyptic number.

31620940 is the 2812-nd decagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31620940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38878560).

31620940 is an abundant number, since it is smaller than the sum of its proper divisors (46136180).

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

31620940 is a wasteful number, since it uses less digits than its factorization.

31620940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251 (or 249 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 31620940 is about 5623.2499499844. The cubic root of 31620940 is about 316.2216438927.

The spelling of 31620940 in words is "thirty-one million, six hundred twenty thousand, nine hundred forty".