21601338204 has 12 divisors (see below), whose sum is σ = 50403122504. Its totient is φ = 7200446064.

The previous prime is 21601338173. The next prime is 21601338223. The reversal of 21601338204 is 40283310612.

It is a tau number, because it is divible by the number of its divisors (12).

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 900055747 + ... + 900055770.

Almost surely, 2^21601338204 is an apocalyptic number.

It is an amenable number.

21601338204 is an abundant number, since it is smaller than the sum of its proper divisors (28801784300).

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

21601338204 is a wasteful number, since it uses less digits than its factorization.

21601338204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1800111524 (or 1800111522 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 30.

Adding to 21601338204 its reverse (40283310612), we get a palindrome (61884648816).

The spelling of 21601338204 in words is "twenty-one billion, six hundred one million, three hundred thirty-eight thousand, two hundred four".