21012524 has 24 divisors (see below), whose sum is σ = 41324640. Its totient is φ = 9275904.

The previous prime is 21012517. The next prime is 21012533. The reversal of 21012524 is 42521012.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7589 + ... + 9980.

It is an arithmetic number, because the mean of its divisors is an integer number (1721860).

Almost surely, 2^21012524 is an apocalyptic number.

It is an amenable number.

21012524 is a deficient number, since it is larger than the sum of its proper divisors (20312116).

21012524 is a wasteful number, since it uses less digits than its factorization.

21012524 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17609 (or 17607 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 21012524 is about 4583.9419717095. The cubic root of 21012524 is about 275.9472523997.

Adding to 21012524 its reverse (42521012), we get a palindrome (63533536).

The spelling of 21012524 in words is "twenty-one million, twelve thousand, five hundred twenty-four".