21524542 has 8 divisors (see below), whose sum is σ = 34770456. Its totient is φ = 9934392.

The previous prime is 21524539. The next prime is 21524593. The reversal of 21524542 is 24542512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 413908 + ... + 413959.

It is an arithmetic number, because the mean of its divisors is an integer number (4346307).

Almost surely, 2^21524542 is an apocalyptic number.

21524542 is a deficient number, since it is larger than the sum of its proper divisors (13245914).

21524542 is a wasteful number, since it uses less digits than its factorization.

21524542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 827882.

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

The square root of 21524542 is about 4639.4549248807. The cubic root of 21524542 is about 278.1706507063.

The spelling of 21524542 in words is "twenty-one million, five hundred twenty-four thousand, five hundred forty-two".