172291409 has 4 divisors (see below), whose sum is σ = 172642800. Its totient is φ = 171940020.

The previous prime is 172291381. The next prime is 172291421. The reversal of 172291409 is 904192271.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 904192271 = 9539 ⋅94789.

It is a cyclic number.

It is not a de Polignac number, because 172291409 - 2¹⁶ = 172225873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (172291429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 174959 + ... + 175940.

It is an arithmetic number, because the mean of its divisors is an integer number (43160700).

Almost surely, 2^172291409 is an apocalyptic number.

It is an amenable number.

172291409 is a deficient number, since it is larger than the sum of its proper divisors (351391).

172291409 is an equidigital number, since it uses as much as digits as its factorization.

172291409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 351390.

The product of its (nonzero) digits is 9072, while the sum is 35.

The square root of 172291409 is about 13125.9822108671. The cubic root of 172291409 is about 556.4436715837.

The spelling of 172291409 in words is "one hundred seventy-two million, two hundred ninety-one thousand, four hundred nine".