172898905 has 4 divisors (see below), whose sum is σ = 207478692. Its totient is φ = 138319120.

The previous prime is 172898897. The next prime is 172898923. The reversal of 172898905 is 509898271.

172898905 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 62900761 + 109998144 = 7931^2 + 10488^2 .

It is not a de Polignac number, because 172898905 - 2³ = 172898897 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17289886 + ... + 17289895.

It is an arithmetic number, because the mean of its divisors is an integer number (51869673).

Almost surely, 2^172898905 is an apocalyptic number.

It is an amenable number.

172898905 is a deficient number, since it is larger than the sum of its proper divisors (34579787).

172898905 is an equidigital number, since it uses as much as digits as its factorization.

172898905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34579786.

The product of its (nonzero) digits is 362880, while the sum is 49.

The square root of 172898905 is about 13149.1028211053. The cubic root of 172898905 is about 557.0969074374.

The spelling of 172898905 in words is "one hundred seventy-two million, eight hundred ninety-eight thousand, nine hundred five".