21214564 has 24 divisors (see below), whose sum is σ = 44663360. Its totient is φ = 8613216.

The previous prime is 21214553. The next prime is 21214577. The reversal of 21214564 is 46541212.

It is a happy number.

It is a super-3 number, since 3×21214564³ (a number of 23 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19407 + ... + 20470.

Almost surely, 2^21214564 is an apocalyptic number.

It is an amenable number.

21214564 is an abundant number, since it is smaller than the sum of its proper divisors (23448796).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21214564 is a wasteful number, since it uses less digits than its factorization.

21214564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39907 (or 39905 counting only the distinct ones).

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

The square root of 21214564 is about 4605.9270510941. The cubic root of 21214564 is about 276.8288637804.

Adding to 21214564 its reverse (46541212), we get a palindrome (67755776).

The spelling of 21214564 in words is "twenty-one million, two hundred fourteen thousand, five hundred sixty-four".