21108524 has 6 divisors (see below), whose sum is σ = 36939924. Its totient is φ = 10554260.

The previous prime is 21108497. The next prime is 21108539. The reversal of 21108524 is 42580112.

It is a self number, because there is not a number n which added to its sum of digits gives 21108524.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2638562 + ... + 2638569.

It is an arithmetic number, because the mean of its divisors is an integer number (6156654).

Almost surely, 2^21108524 is an apocalyptic number.

It is an amenable number.

21108524 is a deficient number, since it is larger than the sum of its proper divisors (15831400).

21108524 is a wasteful number, since it uses less digits than its factorization.

21108524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5277135 (or 5277133 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 23.

The square root of 21108524 is about 4594.4013755875. The cubic root of 21108524 is about 276.3668544623.

Adding to 21108524 its reverse (42580112), we get a palindrome (63688636).

The spelling of 21108524 in words is "twenty-one million, one hundred eight thousand, five hundred twenty-four".