31680840 has 32 divisors (see below), whose sum is σ = 95042880. Its totient is φ = 8448192.

The previous prime is 31680833. The next prime is 31680841. The reversal of 31680840 is 4808613.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 31680798 and 31680807.

It is not an unprimeable number, because it can be changed into a prime (31680841) 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, 131884 + ... + 132123.

It is an arithmetic number, because the mean of its divisors is an integer number (2970090).

Almost surely, 2^31680840 is an apocalyptic number.

31680840 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31680840 is an abundant number, since it is smaller than the sum of its proper divisors (63362040).

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

31680840 is a wasteful number, since it uses less digits than its factorization.

31680840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264021 (or 264017 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 31680840 is about 5628.5735315442. The cubic root of 31680840 is about 316.4211923411.

The spelling of 31680840 in words is "thirty-one million, six hundred eighty thousand, eight hundred forty".