21422564 has 12 divisors (see below), whose sum is σ = 37525488. Its totient is φ = 10701000.

The previous prime is 21422551. The next prime is 21422579. The reversal of 21422564 is 46522412.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3959 + ... + 7649.

It is an arithmetic number, because the mean of its divisors is an integer number (3127124).

Almost surely, 2^21422564 is an apocalyptic number.

It is an amenable number.

21422564 is a deficient number, since it is larger than the sum of its proper divisors (16102924).

21422564 is a wasteful number, since it uses less digits than its factorization.

21422564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5146 (or 5144 counting only the distinct ones).

The product of its digits is 3840, while the sum is 26.

The square root of 21422564 is about 4628.4515769315. The cubic root of 21422564 is about 277.7306536712.

Adding to 21422564 its reverse (46522412), we get a palindrome (67944976).

The spelling of 21422564 in words is "twenty-one million, four hundred twenty-two thousand, five hundred sixty-four".