21372774728255 has 8 divisors (see below), whose sum is σ = 25652399348400. Its totient is φ = 17094839999616.

The previous prime is 21372774728191. The next prime is 21372774728267. The reversal of 21372774728255 is 55282747727312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21372774728255 - 2⁶ = 21372774728191 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 422445050 + ... + 422495639.

It is an arithmetic number, because the mean of its divisors is an integer number (3206549918550).

Almost surely, 2^{21372774728255} is an apocalyptic number.

21372774728255 is a deficient number, since it is larger than the sum of its proper divisors (4279624620145).

21372774728255 is an equidigital number, since it uses as much as digits as its factorization.

21372774728255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 844945753.

The product of its digits is 92198400, while the sum is 62.

The spelling of 21372774728255 in words is "twenty-one trillion, three hundred seventy-two billion, seven hundred seventy-four million, seven hundred twenty-eight thousand, two hundred fifty-five".