172221306 has 16 divisors (see below), whose sum is σ = 355554048. Its totient is φ = 55555200.

The previous prime is 172221299. The next prime is 172221323. The reversal of 172221306 is 603122271.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 462775 + ... + 463146.

It is an arithmetic number, because the mean of its divisors is an integer number (22222128).

Almost surely, 2^172221306 is an apocalyptic number.

172221306 is an abundant number, since it is smaller than the sum of its proper divisors (183332742).

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

172221306 is a wasteful number, since it uses less digits than its factorization.

172221306 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 925957.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 172221306 is about 13123.3115485383. The cubic root of 172221306 is about 556.3681915916.

Adding to 172221306 its reverse (603122271), we get a palindrome (775343577).

It can be divided in two parts, 17222 and 1306, that added together give a triangular number (18528 = T₁₉₂).

The spelling of 172221306 in words is "one hundred seventy-two million, two hundred twenty-one thousand, three hundred six".