21564146 has 8 divisors (see below), whose sum is σ = 32894640. Its totient is φ = 10599268.

The previous prime is 21564131. The next prime is 21564149. The reversal of 21564146 is 64146512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21564149) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 91256 + ... + 91491.

It is an arithmetic number, because the mean of its divisors is an integer number (4111830).

Almost surely, 2^21564146 is an apocalyptic number.

21564146 is a deficient number, since it is larger than the sum of its proper divisors (11330494).

21564146 is a wasteful number, since it uses less digits than its factorization.

21564146 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182808.

The product of its digits is 5760, while the sum is 29.

The square root of 21564146 is about 4643.7211371916. The cubic root of 21564146 is about 278.3411525247.

The spelling of 21564146 in words is "twenty-one million, five hundred sixty-four thousand, one hundred forty-six".