31989723 has 8 divisors (see below), whose sum is σ = 42685200. Its totient is φ = 21310368.

The previous prime is 31989701. The next prime is 31989731. The reversal of 31989723 is 32798913.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 31989723 - 2⁵ = 31989691 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31989773) 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, 1813 + ... + 8201.

It is an arithmetic number, because the mean of its divisors is an integer number (5335650).

Almost surely, 2^31989723 is an apocalyptic number.

31989723 is a deficient number, since it is larger than the sum of its proper divisors (10695477).

31989723 is a wasteful number, since it uses less digits than its factorization.

31989723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8061.

The product of its digits is 81648, while the sum is 42.

The square root of 31989723 is about 5655.9458094999. The cubic root of 31989723 is about 317.4462198367.

It can be divided in two parts, 3198 and 9723, that added together give a palindrome (12921).

The spelling of 31989723 in words is "thirty-one million, nine hundred eighty-nine thousand, seven hundred twenty-three".