228217309 has 2 divisors, whose sum is σ = 228217310. Its totient is φ = 228217308.

The previous prime is 228217273. The next prime is 228217313. The reversal of 228217309 is 903712822.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 176305284 + 51912025 = 13278^2 + 7205^2 .

It is a cyclic number.

It is not a de Polignac number, because 228217309 - 2⁷ = 228217181 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (228217909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 114108654 + 114108655.

It is an arithmetic number, because the mean of its divisors is an integer number (114108655).

Almost surely, 2^228217309 is an apocalyptic number.

It is an amenable number.

228217309 is a deficient number, since it is larger than the sum of its proper divisors (1).

228217309 is an equidigital number, since it uses as much as digits as its factorization.

228217309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 228217309 is about 15106.8629768063. The cubic root of 228217309 is about 611.1055013394.

It can be divided in two parts, 2282 and 17309, that added together give a palindrome (19591).

The spelling of 228217309 in words is "two hundred twenty-eight million, two hundred seventeen thousand, three hundred nine".