172909201 has 2 divisors, whose sum is σ = 172909202. Its totient is φ = 172909200.

The previous prime is 172909199. The next prime is 172909213. The reversal of 172909201 is 102909271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 135699201 + 37210000 = 11649^2 + 6100^2 .

It is a cyclic number.

It is not a de Polignac number, because 172909201 - 2¹ = 172909199 is a prime.

Together with 172909199, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (172909271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86454600 + 86454601.

It is an arithmetic number, because the mean of its divisors is an integer number (86454601).

Almost surely, 2^172909201 is an apocalyptic number.

It is an amenable number.

172909201 is a deficient number, since it is larger than the sum of its proper divisors (1).

172909201 is an equidigital number, since it uses as much as digits as its factorization.

172909201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2268, while the sum is 31.

The square root of 172909201 is about 13149.4943248780. The cubic root of 172909201 is about 557.1079654521.

The spelling of 172909201 in words is "one hundred seventy-two million, nine hundred nine thousand, two hundred one".