21974013 has 24 divisors (see below), whose sum is σ = 35380800. Its totient is φ = 13060224.

The previous prime is 21973981. The next prime is 21974021. The reversal of 21974013 is 31047912.

It is not a de Polignac number, because 21974013 - 2⁵ = 21973981 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21974033) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 873 + ... + 6686.

It is an arithmetic number, because the mean of its divisors is an integer number (1474200).

Almost surely, 2^21974013 is an apocalyptic number.

It is an amenable number.

21974013 is a deficient number, since it is larger than the sum of its proper divisors (13406787).

21974013 is a wasteful number, since it uses less digits than its factorization.

21974013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7601 (or 7598 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 21974013 is about 4687.6447177661. The cubic root of 21974013 is about 280.0935614202.

The spelling of 21974013 in words is "twenty-one million, nine hundred seventy-four thousand, thirteen".