31620420 has 72 divisors (see below), whose sum is σ = 103301016. Its totient is φ = 7782912.

The previous prime is 31620409. The next prime is 31620431. The reversal of 31620420 is 2402613.

It is a happy number.

31620420 is a `hidden beast` number, since 3 + 1 + 620 + 42 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (31620409) and next prime (31620431).

It can be written as a sum of positive squares in 4 ways, for example, as 617796 + 31002624 = 786^2 + 5568^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 31620393 and 31620402.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4417 + ... + 9096.

Almost surely, 2^31620420 is an apocalyptic number.

31620420 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31620420 is an abundant number, since it is smaller than the sum of its proper divisors (71680596).

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

31620420 is a wasteful number, since it uses less digits than its factorization.

31620420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13541 (or 13536 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 31620420 is about 5623.2037131870. The cubic root of 31620420 is about 316.2199104828.

It can be divided in two parts, 316 and 20420, that added together give a 4-th power (20736 = 12⁴).

The spelling of 31620420 in words is "thirty-one million, six hundred twenty thousand, four hundred twenty".