221666106565563 has 16 divisors (see below), whose sum is σ = 322452902928000. Its totient is φ = 134330813556480.

The previous prime is 221666106565489. The next prime is 221666106565609. The reversal of 221666106565563 is 365565601666122.

It is a happy number.

It is not a de Polignac number, because 221666106565563 - 2¹⁷ = 221666106434491 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221666106565497 and 221666106565506.

It is not an unprimeable number, because it can be changed into a prime (221666106563563) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 306666838 + ... + 307388811.

It is an arithmetic number, because the mean of its divisors is an integer number (20153306433000).

Almost surely, 2^{221666106565563} is an apocalyptic number.

221666106565563 is a deficient number, since it is larger than the sum of its proper divisors (100786796362437).

221666106565563 is a wasteful number, since it uses less digits than its factorization.

221666106565563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 614066602.

The product of its (nonzero) digits is 69984000, while the sum is 60.

The spelling of 221666106565563 in words is "two hundred twenty-one trillion, six hundred sixty-six billion, one hundred six million, five hundred sixty-five thousand, five hundred sixty-three".