21022122257 has 2 divisors, whose sum is σ = 21022122258. Its totient is φ = 21022122256.

The previous prime is 21022122211. The next prime is 21022122271. The reversal of 21022122257 is 75222122012.

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., 20633598736 + 388523521 = 143644^2 + 19711^2 .

It is a cyclic number.

It is not a de Polignac number, because 21022122257 - 2²⁴ = 21005345041 is a prime.

It is not a weakly prime, because it can be changed into another prime (21022112257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10511061128 + 10511061129.

It is an arithmetic number, because the mean of its divisors is an integer number (10511061129).

Almost surely, 2^21022122257 is an apocalyptic number.

It is an amenable number.

21022122257 is a deficient number, since it is larger than the sum of its proper divisors (1).

21022122257 is an equidigital number, since it uses as much as digits as its factorization.

21022122257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2240, while the sum is 26.

Adding to 21022122257 its reverse (75222122012), we get a palindrome (96244244269).

The spelling of 21022122257 in words is "twenty-one billion, twenty-two million, one hundred twenty-two thousand, two hundred fifty-seven".