172190905 has 8 divisors (see below), whose sum is σ = 210528072. Its totient is φ = 135153408.

The previous prime is 172190891. The next prime is 172190923. The reversal of 172190905 is 509091271.

172190905 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 24641296 + 147549609 = 4964^2 + 12147^2 .

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 172190905 - 2²⁵ = 138636473 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 324624 + ... + 325153.

It is an arithmetic number, because the mean of its divisors is an integer number (26316009).

Almost surely, 2^172190905 is an apocalyptic number.

It is an amenable number.

172190905 is a deficient number, since it is larger than the sum of its proper divisors (38337167).

172190905 is an equidigital number, since it uses as much as digits as its factorization.

172190905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649835.

The product of its (nonzero) digits is 5670, while the sum is 34.

The square root of 172190905 is about 13122.1532150787. The cubic root of 172190905 is about 556.3354524276.

The spelling of 172190905 in words is "one hundred seventy-two million, one hundred ninety thousand, nine hundred five".