21255342255 has 72 divisors (see below), whose sum is σ = 43854597072. Its totient is φ = 9490715136.

The previous prime is 21255342247. The next prime is 21255342257. The reversal of 21255342255 is 55224355212.

21255342255 is a `hidden beast` number, since 2 + 12 + 55 + 342 + 255 = 666.

It is not a de Polignac number, because 21255342255 - 2³ = 21255342247 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21255342257) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 17274 + ... + 206903.

It is an arithmetic number, because the mean of its divisors is an integer number (609091626).

Almost surely, 2^21255342255 is an apocalyptic number.

21255342255 is an abundant number, since it is smaller than the sum of its proper divisors (22599254817).

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

21255342255 is a wasteful number, since it uses less digits than its factorization.

21255342255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224245 (or 224235 counting only the distinct ones).

The product of its digits is 120000, while the sum is 36.

Adding to 21255342255 its reverse (55224355212), we get a palindrome (76479697467).

The spelling of 21255342255 in words is "twenty-one billion, two hundred fifty-five million, three hundred forty-two thousand, two hundred fifty-five".