21420536255 has 8 divisors (see below), whose sum is σ = 27057519600. Its totient is φ = 16234511616.

The previous prime is 21420536251. The next prime is 21420536257. The reversal of 21420536255 is 55263502412.

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 21420536255 - 2² = 21420536251 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21420536251) 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, 112739570 + ... + 112739759.

It is an arithmetic number, because the mean of its divisors is an integer number (3382189950).

Almost surely, 2^21420536255 is an apocalyptic number.

21420536255 is a deficient number, since it is larger than the sum of its proper divisors (5636983345).

21420536255 is a wasteful number, since it uses less digits than its factorization.

21420536255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225479353.

The product of its (nonzero) digits is 72000, while the sum is 35.

The spelling of 21420536255 in words is "twenty-one billion, four hundred twenty million, five hundred thirty-six thousand, two hundred fifty-five".