31720679 has 4 divisors (see below), whose sum is σ = 31732584. Its totient is φ = 31708776.

The previous prime is 31720673. The next prime is 31720699. The reversal of 31720679 is 97602713.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 97602713 = 13 ⋅7507901.

It is a cyclic number.

It is not a de Polignac number, because 31720679 - 2²⁴ = 14943463 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31720673) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 89 + ... + 7965.

It is an arithmetic number, because the mean of its divisors is an integer number (7933146).

Almost surely, 2^31720679 is an apocalyptic number.

31720679 is a deficient number, since it is larger than the sum of its proper divisors (11905).

31720679 is an equidigital number, since it uses as much as digits as its factorization.

31720679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11904.

The product of its (nonzero) digits is 15876, while the sum is 35.

The square root of 31720679 is about 5632.1114158014. Note that the first 3 decimals coincide. The cubic root of 31720679 is about 316.5537711443.

The spelling of 31720679 in words is "thirty-one million, seven hundred twenty thousand, six hundred seventy-nine".