20217229 has 2 divisors, whose sum is σ = 20217230. Its totient is φ = 20217228.

The previous prime is 20217209. The next prime is 20217259. The reversal of 20217229 is 92271202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19448100 + 769129 = 4410^2 + 877^2 .

It is a cyclic number.

It is not a de Polignac number, because 20217229 - 2⁷ = 20217101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20217209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10108614 + 10108615.

It is an arithmetic number, because the mean of its divisors is an integer number (10108615).

Almost surely, 2^20217229 is an apocalyptic number.

It is an amenable number.

20217229 is a deficient number, since it is larger than the sum of its proper divisors (1).

20217229 is an equidigital number, since it uses as much as digits as its factorization.

20217229 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 20217229 is about 4496.3573034180. The cubic root of 20217229 is about 272.4209753176.

The spelling of 20217229 in words is "twenty million, two hundred seventeen thousand, two hundred twenty-nine".