21264562 has 16 divisors (see below), whose sum is σ = 34867584. Its totient is φ = 9646000.

The previous prime is 21264559. The next prime is 21264563. The reversal of 21264562 is 26546212.

It is a self number, because there is not a number n which added to its sum of digits gives 21264562.

It is not an unprimeable number, because it can be changed into a prime (21264563) 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 7 ways as a sum of consecutive naturals, for example, 19512 + ... + 20572.

It is an arithmetic number, because the mean of its divisors is an integer number (2179224).

Almost surely, 2^21264562 is an apocalyptic number.

21264562 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21264562 is a deficient number, since it is larger than the sum of its proper divisors (13603022).

21264562 is a wasteful number, since it uses less digits than its factorization.

21264562 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1985.

The product of its digits is 5760, while the sum is 28.

The square root of 21264562 is about 4611.3514288113. The cubic root of 21264562 is about 277.0461678055.

The spelling of 21264562 in words is "twenty-one million, two hundred sixty-four thousand, five hundred sixty-two".