21524642 has 8 divisors (see below), whose sum is σ = 33690816. Its totient is φ = 10294372.

The previous prime is 21524623. The next prime is 21524647. The reversal of 21524642 is 24642512.

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

It is not an unprimeable number, because it can be changed into a prime (21524647) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 233918 + ... + 234009.

It is an arithmetic number, because the mean of its divisors is an integer number (4211352).

Almost surely, 2^21524642 is an apocalyptic number.

21524642 is a deficient number, since it is larger than the sum of its proper divisors (12166174).

21524642 is a wasteful number, since it uses less digits than its factorization.

21524642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 467952.

The product of its digits is 3840, while the sum is 26.

The square root of 21524642 is about 4639.4657019963. The cubic root of 21524642 is about 278.1710814863.

The spelling of 21524642 in words is "twenty-one million, five hundred twenty-four thousand, six hundred forty-two".