21357955168 has 96 divisors (see below), whose sum is σ = 48701399040. Its totient is φ = 9112258560.

The previous prime is 21357955159. The next prime is 21357955243. The reversal of 21357955168 is 86155975312.

It is a happy 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, 2287213 + ... + 2296531.

It is an arithmetic number, because the mean of its divisors is an integer number (507306240).

Almost surely, 2^21357955168 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21357955168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24350699520).

21357955168 is an abundant number, since it is smaller than the sum of its proper divisors (27343443872).

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

21357955168 is a wasteful number, since it uses less digits than its factorization.

21357955168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9740 (or 9732 counting only the distinct ones).

The product of its digits is 2268000, while the sum is 52.

The spelling of 21357955168 in words is "twenty-one billion, three hundred fifty-seven million, nine hundred fifty-five thousand, one hundred sixty-eight".