21852538 has 16 divisors (see below), whose sum is σ = 33660000. Its totient is φ = 10636272.

The previous prime is 21852529. The next prime is 21852539. The reversal of 21852538 is 83525812.

It is not an unprimeable number, because it can be changed into a prime (21852539) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12013 + ... + 13711.

It is an arithmetic number, because the mean of its divisors is an integer number (2103750).

Almost surely, 2^21852538 is an apocalyptic number.

21852538 is a deficient number, since it is larger than the sum of its proper divisors (11807462).

21852538 is a wasteful number, since it uses less digits than its factorization.

21852538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1869.

The product of its digits is 19200, while the sum is 34.

The square root of 21852538 is about 4674.6698279130. The cubic root of 21852538 is about 279.5764770568.

The spelling of 21852538 in words is "twenty-one million, eight hundred fifty-two thousand, five hundred thirty-eight".