31623643 has 4 divisors (see below), whose sum is σ = 32998608. Its totient is φ = 30248680.

The previous prime is 31623623. The next prime is 31623667. The reversal of 31623643 is 34632613.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-31623643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31623623) 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, 687448 + ... + 687493.

It is an arithmetic number, because the mean of its divisors is an integer number (8249652).

Almost surely, 2^31623643 is an apocalyptic number.

31623643 is a deficient number, since it is larger than the sum of its proper divisors (1374965).

31623643 is a wasteful number, since it uses less digits than its factorization.

31623643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1374964.

The product of its digits is 7776, while the sum is 28.

The square root of 31623643 is about 5623.4902862902. The cubic root of 31623643 is about 316.2306539849.

The spelling of 31623643 in words is "thirty-one million, six hundred twenty-three thousand, six hundred forty-three".