172725809 has 2 divisors, whose sum is σ = 172725810. Its totient is φ = 172725808.

The previous prime is 172725793. The next prime is 172725821. The reversal of 172725809 is 908527271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 100560784 + 72165025 = 10028^2 + 8495^2 .

It is an emirp because it is prime and its reverse (908527271) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 172725809 - 2⁴ = 172725793 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (172725829) 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, 86362904 + 86362905.

It is an arithmetic number, because the mean of its divisors is an integer number (86362905).

Almost surely, 2^172725809 is an apocalyptic number.

It is an amenable number.

172725809 is a deficient number, since it is larger than the sum of its proper divisors (1).

172725809 is an equidigital number, since it uses as much as digits as its factorization.

172725809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 70560, while the sum is 41.

The square root of 172725809 is about 13142.5191268645. The cubic root of 172725809 is about 556.9109347065.

The spelling of 172725809 in words is "one hundred seventy-two million, seven hundred twenty-five thousand, eight hundred nine".