21874189638 has 32 divisors (see below), whose sum is σ = 50702353920. Its totient is φ = 6161742720.

The previous prime is 21874189621. The next prime is 21874189699. The reversal of 21874189638 is 83698147812.

It is an alternating number because its digits alternate between even and odd.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3664723 + ... + 3670686.

It is an arithmetic number, because the mean of its divisors is an integer number (1584448560).

Almost surely, 2^21874189638 is an apocalyptic number.

21874189638 is an abundant number, since it is smaller than the sum of its proper divisors (28828164282).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21874189638 is a wasteful number, since it uses less digits than its factorization.

21874189638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7335492.

The product of its digits is 4644864, while the sum is 57.

The spelling of 21874189638 in words is "twenty-one billion, eight hundred seventy-four million, one hundred eighty-nine thousand, six hundred thirty-eight".