21112323257 has 2 divisors, whose sum is σ = 21112323258. Its totient is φ = 21112323256.

The previous prime is 21112323227. The next prime is 21112323259. The reversal of 21112323257 is 75232321112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16940584336 + 4171738921 = 130156^2 + 64589^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112323257 - 2¹² = 21112319161 is a prime.

Together with 21112323259, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21112323259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556161628 + 10556161629.

It is an arithmetic number, because the mean of its divisors is an integer number (10556161629).

Almost surely, 2^21112323257 is an apocalyptic number.

It is an amenable number.

21112323257 is a deficient number, since it is larger than the sum of its proper divisors (1).

21112323257 is an equidigital number, since it uses as much as digits as its factorization.

21112323257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5040, while the sum is 29.

Adding to 21112323257 its reverse (75232321112), we get a palindrome (96344644369).

The spelling of 21112323257 in words is "twenty-one billion, one hundred twelve million, three hundred twenty-three thousand, two hundred fifty-seven".