21456522223057 has 2 divisors, whose sum is σ = 21456522223058. Its totient is φ = 21456522223056.

The previous prime is 21456522222977. The next prime is 21456522223067. The reversal of 21456522223057 is 75032222565412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19743483636496 + 1713038586561 = 4443364^2 + 1308831^2 .

It is a cyclic number.

It is not a de Polignac number, because 21456522223057 - 2¹⁹ = 21456521698769 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21456522222998 and 21456522223016.

It is not a weakly prime, because it can be changed into another prime (21456522223067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10728261111528 + 10728261111529.

It is an arithmetic number, because the mean of its divisors is an integer number (10728261111529).

Almost surely, 2^{21456522223057} is an apocalyptic number.

It is an amenable number.

21456522223057 is a deficient number, since it is larger than the sum of its proper divisors (1).

21456522223057 is an equidigital number, since it uses as much as digits as its factorization.

21456522223057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2016000, while the sum is 46.

Adding to 21456522223057 its reverse (75032222565412), we get a palindrome (96488744788469).

The spelling of 21456522223057 in words is "twenty-one trillion, four hundred fifty-six billion, five hundred twenty-two million, two hundred twenty-three thousand, fifty-seven".