221605502424561 has 12 divisors (see below), whose sum is σ = 320097386673792. Its totient is φ = 147736747844856.

The previous prime is 221605502424529. The next prime is 221605502424599. The reversal of 221605502424561 is 165424205506122.

221605502424561 is a `hidden beast` number, since 2 + 2 + 1 + 6 + 0 + 5 + 502 + 42 + 45 + 61 = 666.

It is not a de Polignac number, because 221605502424561 - 2⁵ = 221605502424529 is a prime.

It is a super-2 number, since 2×221605502424561² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221605502424521) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15538761 + ... + 26166086.

It is an arithmetic number, because the mean of its divisors is an integer number (26674782222816).

Almost surely, 2^{221605502424561} is an apocalyptic number.

It is an amenable number.

221605502424561 is a deficient number, since it is larger than the sum of its proper divisors (98491884249231).

221605502424561 is a wasteful number, since it uses less digits than its factorization.

221605502424561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42295260 (or 42295257 counting only the distinct ones).

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

The spelling of 221605502424561 in words is "two hundred twenty-one trillion, six hundred five billion, five hundred two million, four hundred twenty-four thousand, five hundred sixty-one".