21542524 has 12 divisors (see below), whose sum is σ = 38052504. Its totient is φ = 10670384.

The previous prime is 21542483. The next prime is 21542537. The reversal of 21542524 is 42524512.

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 in 3 ways as a sum of consecutive naturals, for example, 24739 + ... + 25594.

It is an arithmetic number, because the mean of its divisors is an integer number (3171042).

Almost surely, 2^21542524 is an apocalyptic number.

It is an amenable number.

21542524 is a deficient number, since it is larger than the sum of its proper divisors (16509980).

21542524 is a wasteful number, since it uses less digits than its factorization.

21542524 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50444 (or 50442 counting only the distinct ones).

The product of its digits is 3200, while the sum is 25.

The square root of 21542524 is about 4641.3924634747. The cubic root of 21542524 is about 278.2480921117.

The spelling of 21542524 in words is "twenty-one million, five hundred forty-two thousand, five hundred twenty-four".