21731974 has 16 divisors (see below), whose sum is σ = 35641296. Its totient is φ = 9856000.

The previous prime is 21731971. The next prime is 21731981. The reversal of 21731974 is 47913712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21731971) 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, 12774 + ... + 14374.

It is an arithmetic number, because the mean of its divisors is an integer number (2227581).

Almost surely, 2^21731974 is an apocalyptic number.

21731974 is a deficient number, since it is larger than the sum of its proper divisors (13909322).

21731974 is a wasteful number, since it uses less digits than its factorization.

21731974 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2231.

The product of its digits is 10584, while the sum is 34.

The square root of 21731974 is about 4661.7565358993. The cubic root of 21731974 is about 279.0613723152.

The spelling of 21731974 in words is "twenty-one million, seven hundred thirty-one thousand, nine hundred seventy-four".