172906 has 4 divisors (see below), whose sum is σ = 259362. Its totient is φ = 86452.

The previous prime is 172883. The next prime is 172933. The reversal of 172906 is 609271.

172906 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, and also an emirpimes, since its reverse is a distinct semiprime: 609271 = 13 ⋅46867.

It can be written as a sum of positive squares in only one way, i.e., 167281 + 5625 = 409^2 + 75^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43225 + ... + 43228.

2¹⁷²⁹⁰⁶ is an apocalyptic number.

172906 is a deficient number, since it is larger than the sum of its proper divisors (86456).

172906 is an equidigital number, since it uses as much as digits as its factorization.

172906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86455.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 172906 is about 415.8196724543. The cubic root of 172906 is about 55.7104527591.

It can be divided in two parts, 17290 and 6, that multiplied together give a triangular number (103740 = T₄₅₅).

The spelling of 172906 in words is "one hundred seventy-two thousand, nine hundred six".