172331305 has 4 divisors (see below), whose sum is σ = 206797572. Its totient is φ = 137865040.

The previous prime is 172331297. The next prime is 172331309. The reversal of 172331305 is 503133271.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 503133271 = 5431 ⋅92641.

It can be written as a sum of positive squares in 2 ways, for example, as 19289664 + 153041641 = 4392^2 + 12371^2 .

It is not a de Polignac number, because 172331305 - 2³ = 172331297 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 172331305.

It is not an unprimeable number, because it can be changed into a prime (172331309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17233126 + ... + 17233135.

It is an arithmetic number, because the mean of its divisors is an integer number (51699393).

Almost surely, 2^172331305 is an apocalyptic number.

It is an amenable number.

172331305 is a deficient number, since it is larger than the sum of its proper divisors (34466267).

172331305 is an equidigital number, since it uses as much as digits as its factorization.

172331305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34466266.

The product of its (nonzero) digits is 1890, while the sum is 25.

The square root of 172331305 is about 13127.5018567891. The cubic root of 172331305 is about 556.4866185179.

Adding to 172331305 its reverse (503133271), we get a palindrome (675464576).

The spelling of 172331305 in words is "one hundred seventy-two million, three hundred thirty-one thousand, three hundred five".