21972146 has 32 divisors (see below), whose sum is σ = 39070080. Its totient is φ = 9072000.

The previous prime is 21972127. The next prime is 21972173. The reversal of 21972146 is 64127912.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57785 + ... + 58163.

It is an arithmetic number, because the mean of its divisors is an integer number (1220940).

Almost surely, 2^21972146 is an apocalyptic number.

21972146 is a deficient number, since it is larger than the sum of its proper divisors (17097934).

21972146 is a wasteful number, since it uses less digits than its factorization.

21972146 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 530.

The product of its digits is 6048, while the sum is 32.

The square root of 21972146 is about 4687.4455730174. The cubic root of 21972146 is about 280.0856285726.

The spelling of 21972146 in words is "twenty-one million, nine hundred seventy-two thousand, one hundred forty-six".