172351221 has 16 divisors (see below), whose sum is σ = 262813824. Its totient is φ = 98417664.

The previous prime is 172351199. The next prime is 172351237. The reversal of 172351221 is 122153271.

It is not a de Polignac number, because 172351221 - 2¹⁵ = 172318453 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 172351191 and 172351200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172351241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 58045 + ... + 60941.

It is an arithmetic number, because the mean of its divisors is an integer number (16425864).

Almost surely, 2^172351221 is an apocalyptic number.

It is an amenable number.

172351221 is a deficient number, since it is larger than the sum of its proper divisors (90462603).

172351221 is a wasteful number, since it uses less digits than its factorization.

172351221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5740.

The product of its digits is 840, while the sum is 24.

The square root of 172351221 is about 13128.2603950409. The cubic root of 172351221 is about 556.5080550575.

The spelling of 172351221 in words is "one hundred seventy-two million, three hundred fifty-one thousand, two hundred twenty-one".