211221002257 has 2 divisors, whose sum is σ = 211221002258. Its totient is φ = 211221002256.

The previous prime is 211221002191. The next prime is 211221002281. The reversal of 211221002257 is 752200122112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 198237767121 + 12983235136 = 445239^2 + 113944^2 .

It is a cyclic number.

It is not a de Polignac number, because 211221002257 - 2²⁷ = 211086784529 is a prime.

It is a super-2 number, since 2×211221002257² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (211221002287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105610501128 + 105610501129.

It is an arithmetic number, because the mean of its divisors is an integer number (105610501129).

Almost surely, 2^211221002257 is an apocalyptic number.

It is an amenable number.

211221002257 is a deficient number, since it is larger than the sum of its proper divisors (1).

211221002257 is an equidigital number, since it uses as much as digits as its factorization.

211221002257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1120, while the sum is 25.

Adding to 211221002257 its reverse (752200122112), we get a palindrome (963421124369).

The spelling of 211221002257 in words is "two hundred eleven billion, two hundred twenty-one million, two thousand, two hundred fifty-seven".