21355793868 has 24 divisors (see below), whose sum is σ = 49833387072. Its totient is φ = 7118140624.

The previous prime is 21355793863. The next prime is 21355793881. The reversal of 21355793868 is 86839755312.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21355793863) 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, 175171 + ... + 270917.

It is an arithmetic number, because the mean of its divisors is an integer number (2076391128).

Almost surely, 2^21355793868 is an apocalyptic number.

It is an amenable number.

21355793868 is an abundant number, since it is smaller than the sum of its proper divisors (28477593204).

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

21355793868 is a wasteful number, since it uses less digits than its factorization.

21355793868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114341 (or 114339 counting only the distinct ones).

The product of its digits is 10886400, while the sum is 57.

The spelling of 21355793868 in words is "twenty-one billion, three hundred fifty-five million, seven hundred ninety-three thousand, eight hundred sixty-eight".