21564214 has 24 divisors (see below), whose sum is σ = 37806048. Its totient is φ = 9198000.

The previous prime is 21564203. The next prime is 21564217. The reversal of 21564214 is 41246512.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21564217) 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 11 ways as a sum of consecutive naturals, for example, 28339 + ... + 29089.

It is an arithmetic number, because the mean of its divisors is an integer number (1575252).

Almost surely, 2^21564214 is an apocalyptic number.

21564214 is a deficient number, since it is larger than the sum of its proper divisors (16241834).

21564214 is a wasteful number, since it uses less digits than its factorization.

21564214 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1060 (or 1053 counting only the distinct ones).

The product of its digits is 1920, while the sum is 25.

The square root of 21564214 is about 4643.7284589002. The cubic root of 21564214 is about 278.3414450965.

The spelling of 21564214 in words is "twenty-one million, five hundred sixty-four thousand, two hundred fourteen".