172993209 has 4 divisors (see below), whose sum is σ = 230657616. Its totient is φ = 115328804.

The previous prime is 172993201. The next prime is 172993211. The reversal of 172993209 is 902399271.

It is a happy number.

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: 902399271 = 3 ⋅300799757.

It is a cyclic number.

It is not a de Polignac number, because 172993209 - 2³ = 172993201 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (172993201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28832199 + ... + 28832204.

It is an arithmetic number, because the mean of its divisors is an integer number (57664404).

Almost surely, 2^172993209 is an apocalyptic number.

It is an amenable number.

172993209 is a deficient number, since it is larger than the sum of its proper divisors (57664407).

172993209 is an equidigital number, since it uses as much as digits as its factorization.

172993209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57664406.

The product of its (nonzero) digits is 61236, while the sum is 42.

The square root of 172993209 is about 13152.6882803479. The cubic root of 172993209 is about 557.1981745488.

The spelling of 172993209 in words is "one hundred seventy-two million, nine hundred ninety-three thousand, two hundred nine".