21323122056553 has 2 divisors, whose sum is σ = 21323122056554. Its totient is φ = 21323122056552.

The previous prime is 21323122056541. The next prime is 21323122056571. The reversal of 21323122056553 is 35565022132312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12725864732889 + 8597257323664 = 3567333^2 + 2932108^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21323122056553 is a prime.

It is not a weakly prime, because it can be changed into another prime (21323122056053) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10661561028276 + 10661561028277.

It is an arithmetic number, because the mean of its divisors is an integer number (10661561028277).

Almost surely, 2^{21323122056553} is an apocalyptic number.

It is an amenable number.

21323122056553 is a deficient number, since it is larger than the sum of its proper divisors (1).

21323122056553 is an equidigital number, since it uses as much as digits as its factorization.

21323122056553 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324000, while the sum is 40.

Adding to 21323122056553 its reverse (35565022132312), we get a palindrome (56888144188865).

The spelling of 21323122056553 in words is "twenty-one trillion, three hundred twenty-three billion, one hundred twenty-two million, fifty-six thousand, five hundred fifty-three".