21604918837138 has 32 divisors (see below), whose sum is σ = 40700004105600. Its totient is φ = 8547000855120.

The previous prime is 21604918837121. The next prime is 21604918837153. The reversal of 21604918837138 is 83173881940612.

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, 1211300728 + ... + 1211318563.

It is an arithmetic number, because the mean of its divisors is an integer number (1271875128300).

Almost surely, 2^{21604918837138} is an apocalyptic number.

21604918837138 is a deficient number, since it is larger than the sum of its proper divisors (19095085268462).

21604918837138 is a wasteful number, since it uses less digits than its factorization.

21604918837138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2422619327 (or 2422619313 counting only the distinct ones).

The product of its (nonzero) digits is 13934592, while the sum is 61.

The spelling of 21604918837138 in words is "twenty-one trillion, six hundred four billion, nine hundred eighteen million, eight hundred thirty-seven thousand, one hundred thirty-eight".