21126524 has 6 divisors (see below), whose sum is σ = 36971424. Its totient is φ = 10563260.

The previous prime is 21126517. The next prime is 21126533. The reversal of 21126524 is 42562112.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21126524.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2640812 + ... + 2640819.

It is an arithmetic number, because the mean of its divisors is an integer number (6161904).

Almost surely, 2^21126524 is an apocalyptic number.

It is an amenable number.

21126524 is a deficient number, since it is larger than the sum of its proper divisors (15844900).

21126524 is a wasteful number, since it uses less digits than its factorization.

21126524 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5281635 (or 5281633 counting only the distinct ones).

The product of its digits is 960, while the sum is 23.

The square root of 21126524 is about 4596.3598640663. The cubic root of 21126524 is about 276.4453881397.

Adding to 21126524 its reverse (42562112), we get a palindrome (63688636).

The spelling of 21126524 in words is "twenty-one million, one hundred twenty-six thousand, five hundred twenty-four".