172808905 has 8 divisors (see below), whose sum is σ = 209869632. Its totient is φ = 136581168.

The previous prime is 172808903. The next prime is 172808917. The reversal of 172808905 is 509808271.

172808905 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 172808905 - 2¹ = 172808903 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (172808903) 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, 207789 + ... + 208618.

It is an arithmetic number, because the mean of its divisors is an integer number (26233704).

Almost surely, 2^172808905 is an apocalyptic number.

It is an amenable number.

172808905 is a deficient number, since it is larger than the sum of its proper divisors (37060727).

172808905 is an equidigital number, since it uses as much as digits as its factorization.

172808905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 416495.

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 172808905 is about 13145.6800889113. The cubic root of 172808905 is about 557.0002277739. Note that the first 3 decimals are identical.

The spelling of 172808905 in words is "one hundred seventy-two million, eight hundred eight thousand, nine hundred five".