217172249 has 4 divisors (see below), whose sum is σ = 248196864. Its totient is φ = 186147636.

The previous prime is 217172237. The next prime is 217172257. The reversal of 217172249 is 942271712.

217172249 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 a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 217172249 - 2²⁰ = 216123673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (217172269) 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, 15512297 + ... + 15512310.

It is an arithmetic number, because the mean of its divisors is an integer number (62049216).

Almost surely, 2^217172249 is an apocalyptic number.

It is an amenable number.

217172249 is a deficient number, since it is larger than the sum of its proper divisors (31024615).

217172249 is an equidigital number, since it uses as much as digits as its factorization.

217172249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31024614.

The product of its digits is 14112, while the sum is 35.

The square root of 217172249 is about 14736.7652149310. The cubic root of 217172249 is about 601.0834580940.

The spelling of 217172249 in words is "two hundred seventeen million, one hundred seventy-two thousand, two hundred forty-nine".