172328509 has 2 divisors, whose sum is σ = 172328510. Its totient is φ = 172328508.

The previous prime is 172328479. The next prime is 172328531. The reversal of 172328509 is 905823271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 165199609 + 7128900 = 12853^2 + 2670^2 .

It is a cyclic number.

It is not a de Polignac number, because 172328509 - 2¹⁵ = 172295741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172328539) by changing a digit.

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 as a sum of consecutive naturals, namely, 86164254 + 86164255.

It is an arithmetic number, because the mean of its divisors is an integer number (86164255).

Almost surely, 2^172328509 is an apocalyptic number.

It is an amenable number.

172328509 is a deficient number, since it is larger than the sum of its proper divisors (1).

172328509 is an equidigital number, since it uses as much as digits as its factorization.

172328509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30240, while the sum is 37.

The square root of 172328509 is about 13127.3953623710. The cubic root of 172328509 is about 556.4836089176.

The spelling of 172328509 in words is "one hundred seventy-two million, three hundred twenty-eight thousand, five hundred nine".