21979174 has 16 divisors (see below), whose sum is σ = 38481408. Its totient is φ = 9218952.

The previous prime is 21979169. The next prime is 21979189. The reversal of 21979174 is 47197912.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16044 + ... + 17359.

It is an arithmetic number, because the mean of its divisors is an integer number (2405088).

Almost surely, 2^21979174 is an apocalyptic number.

21979174 is a deficient number, since it is larger than the sum of its proper divisors (16502234).

21979174 is a wasteful number, since it uses less digits than its factorization.

21979174 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33459.

The product of its digits is 31752, while the sum is 40.

The square root of 21979174 is about 4688.1951751180. The cubic root of 21979174 is about 280.1154880738.

The spelling of 21979174 in words is "twenty-one million, nine hundred seventy-nine thousand, one hundred seventy-four".