221671659946465 has 16 divisors (see below), whose sum is σ = 267223855344336. Its totient is φ = 176526047692800.

The previous prime is 221671659946423. The next prime is 221671659946493. The reversal of 221671659946465 is 564649956176122.

It can be written as a sum of positive squares in 8 ways, for example, as 127457568144 + 221544202378321 = 357012^2 + 14884361^2 .

It is not a de Polignac number, because 221671659946465 - 2⁷ = 221671659946337 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36469972 + ... + 42111781.

It is an arithmetic number, because the mean of its divisors is an integer number (16701490959021).

Almost surely, 2^{221671659946465} is an apocalyptic number.

It is an amenable number.

221671659946465 is a deficient number, since it is larger than the sum of its proper divisors (45552195397871).

221671659946465 is a wasteful number, since it uses less digits than its factorization.

221671659946465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78584340.

The product of its digits is 1175731200, while the sum is 73.

The spelling of 221671659946465 in words is "two hundred twenty-one trillion, six hundred seventy-one billion, six hundred fifty-nine million, nine hundred forty-six thousand, four hundred sixty-five".