31620020 has 24 divisors (see below), whose sum is σ = 68023368. Its totient is φ = 12339200.

The previous prime is 31620019. The next prime is 31620037. The reversal of 31620020 is 2002613.

It can be written as a sum of positive squares in 4 ways, for example, as 327184 + 31292836 = 572^2 + 5594^2 .

It is a junction number, because it is equal to n+sod(n) for n = 31619977 and 31620004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18461 + ... + 20100.

It is an arithmetic number, because the mean of its divisors is an integer number (2834307).

Almost surely, 2^31620020 is an apocalyptic number.

It is an amenable number.

31620020 is an abundant number, since it is smaller than the sum of its proper divisors (36403348).

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

31620020 is a wasteful number, since it uses less digits than its factorization.

31620020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38611 (or 38609 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 31620020 is about 5623.1681461610. The cubic root of 31620020 is about 316.2185770775.

Adding to 31620020 its reverse (2002613), we get a palindrome (33622633).

The spelling of 31620020 in words is "thirty-one million, six hundred twenty thousand, twenty".