228996221 has 2 divisors, whose sum is σ = 228996222. Its totient is φ = 228996220.

The previous prime is 228996197. The next prime is 228996223. The reversal of 228996221 is 122699822.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 147744025 + 81252196 = 12155^2 + 9014^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-228996221 is a prime.

Together with 228996223, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (228996223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 114498110 + 114498111.

It is an arithmetic number, because the mean of its divisors is an integer number (114498111).

Almost surely, 2^228996221 is an apocalyptic number.

It is an amenable number.

228996221 is a deficient number, since it is larger than the sum of its proper divisors (1).

228996221 is an equidigital number, since it uses as much as digits as its factorization.

228996221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 62208, while the sum is 41.

The square root of 228996221 is about 15132.6210882319. The cubic root of 228996221 is about 611.7999518816.

The spelling of 228996221 in words is "two hundred twenty-eight million, nine hundred ninety-six thousand, two hundred twenty-one".