21221445606255 has 24 divisors (see below), whose sum is σ = 36784636293600. Its totient is φ = 11317859017920.

The previous prime is 21221445606253. The next prime is 21221445606281. The reversal of 21221445606255 is 55260654412212.

21221445606255 is a `hidden beast` number, since 2 + 1 + 2 + 2 + 14 + 4 + 5 + 6 + 0 + 625 + 5 = 666.

It is not a de Polignac number, because 21221445606255 - 2¹ = 21221445606253 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 21221445606255.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221445606253) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3001651 + ... + 7173060.

It is an arithmetic number, because the mean of its divisors is an integer number (1532693178900).

Almost surely, 2^{21221445606255} is an apocalyptic number.

21221445606255 is a deficient number, since it is larger than the sum of its proper divisors (15563190687345).

21221445606255 is a wasteful number, since it uses less digits than its factorization.

21221445606255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10221071 (or 10221068 counting only the distinct ones).

The product of its (nonzero) digits is 1152000, while the sum is 45.

The spelling of 21221445606255 in words is "twenty-one trillion, two hundred twenty-one billion, four hundred forty-five million, six hundred six thousand, two hundred fifty-five".