31980720 has 40 divisors (see below), whose sum is σ = 99140976. Its totient is φ = 8528128.

The previous prime is 31980719. The next prime is 31980721. The reversal of 31980720 is 2708913.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (31980719) and next prime (31980721).

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (31980721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66387 + ... + 66866.

Almost surely, 2^31980720 is an apocalyptic number.

31980720 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31980720 is an abundant number, since it is smaller than the sum of its proper divisors (67160256).

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

31980720 is a wasteful number, since it uses less digits than its factorization.

31980720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133269 (or 133263 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 31980720 is about 5655.1498653882. The cubic root of 31980720 is about 317.4164369752.

The spelling of 31980720 in words is "thirty-one million, nine hundred eighty thousand, seven hundred twenty".