221845172 has 12 divisors (see below), whose sum is σ = 411066180. Its totient is φ = 104397696.

The previous prime is 221845171. The next prime is 221845181. The reversal of 221845172 is 271548122.

221845172 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 89226916 + 132618256 = 9446^2 + 11516^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221845171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1631147 + ... + 1631282.

It is an arithmetic number, because the mean of its divisors is an integer number (34255515).

Almost surely, 2^221845172 is an apocalyptic number.

It is an amenable number.

221845172 is a deficient number, since it is larger than the sum of its proper divisors (189221008).

221845172 is a wasteful number, since it uses less digits than its factorization.

221845172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3262450 (or 3262448 counting only the distinct ones).

The product of its digits is 8960, while the sum is 32.

The square root of 221845172 is about 14894.4678320509. The cubic root of 221845172 is about 605.3640974821.

The spelling of 221845172 in words is "two hundred twenty-one million, eight hundred forty-five thousand, one hundred seventy-two".