172808809 has 8 divisors (see below), whose sum is σ = 177768360. Its totient is φ = 167884800.

The previous prime is 172808807. The next prime is 172808813. The reversal of 172808809 is 908808271.

172808809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 3080025 + 169728784 = 1755^2 + 13028^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 172808809 - 2¹ = 172808807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (172808803) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1137 + ... + 18625.

It is an arithmetic number, because the mean of its divisors is an integer number (22221045).

Almost surely, 2^172808809 is an apocalyptic number.

It is an amenable number.

172808809 is a deficient number, since it is larger than the sum of its proper divisors (4959551).

172808809 is a wasteful number, since it uses less digits than its factorization.

172808809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17771.

The product of its (nonzero) digits is 64512, while the sum is 43.

The square root of 172808809 is about 13145.6764375212. The cubic root of 172808809 is about 557.0001246310. Note that the first 3 decimals are identical.

The spelling of 172808809 in words is "one hundred seventy-two million, eight hundred eight thousand, eight hundred nine".