221825166165 has 32 divisors (see below), whose sum is σ = 399910176000. Its totient is φ = 116640457920.

The previous prime is 221825166109. The next prime is 221825166203. The reversal of 221825166165 is 561661528122.

221825166165 is a `hidden beast` number, since 2 + 2 + 1 + 8 + 25 + 1 + 6 + 616 + 5 = 666.

It is not a de Polignac number, because 221825166165 - 2⁷ = 221825166037 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 221825166165.

It is a congruent 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 31 ways as a sum of consecutive naturals, for example, 11561890 + ... + 11581059.

It is an arithmetic number, because the mean of its divisors is an integer number (12497193000).

Almost surely, 2^221825166165 is an apocalyptic number.

It is an amenable number.

221825166165 is a deficient number, since it is larger than the sum of its proper divisors (178085009835).

221825166165 is a wasteful number, since it uses less digits than its factorization.

221825166165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23143034 (or 23143028 counting only the distinct ones).

The product of its digits is 345600, while the sum is 45.

The spelling of 221825166165 in words is "two hundred twenty-one billion, eight hundred twenty-five million, one hundred sixty-six thousand, one hundred sixty-five".