222721164 has 42 divisors (see below), whose sum is σ = 584383380. Its totient is φ = 74239416.

The previous prime is 222721157. The next prime is 222721181. The reversal of 222721164 is 461127222.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 35274 + ... + 41105.

It is an arithmetic number, because the mean of its divisors is an integer number (13913890).

Almost surely, 2^222721164 is an apocalyptic number.

It is an amenable number.

222721164 is an abundant number, since it is smaller than the sum of its proper divisors (361662216).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

222721164 is an equidigital number, since it uses as much as digits as its factorization.

222721164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76401 (or 76384 counting only the distinct ones).

The product of its digits is 2688, while the sum is 27.

The square root of 222721164 is about 14923.8454829846. The cubic root of 222721164 is about 606.1598441200.

Adding to 222721164 its reverse (461127222), we get a palindrome (683848386).

It can be divided in two parts, 22272 and 1164, that added together give a triangular number (23436 = T₂₁₆).

The spelling of 222721164 in words is "two hundred twenty-two million, seven hundred twenty-one thousand, one hundred sixty-four".