31430720 has 28 divisors (see below), whose sum is σ = 74845164. Its totient is φ = 12572160.

The previous prime is 31430717. The next prime is 31430743. The reversal of 31430720 is 2703413.

It can be written as a sum of positive squares in 2 ways, for example, as 6190144 + 25240576 = 2488^2 + 5024^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 31430692 and 31430701.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48791 + ... + 49430.

Almost surely, 2^31430720 is an apocalyptic number.

It is an amenable number.

31430720 is an abundant number, since it is smaller than the sum of its proper divisors (43414444).

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

31430720 is an equidigital number, since it uses as much as digits as its factorization.

31430720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98238 (or 98228 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 20.

The square root of 31430720 is about 5606.3107298829. The cubic root of 31430720 is about 315.5862769211.

The spelling of 31430720 in words is "thirty-one million, four hundred thirty thousand, seven hundred twenty".