21326057569 has 2 divisors, whose sum is σ = 21326057570. Its totient is φ = 21326057568.

The previous prime is 21326057563. The next prime is 21326057573. The reversal of 21326057569 is 96575062312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17715610000 + 3610447569 = 133100^2 + 60087^2 .

It is a cyclic number.

It is not a de Polignac number, because 21326057569 - 2⁹ = 21326057057 is a prime.

It is a super-2 number, since 2×21326057569² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21326057563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10663028784 + 10663028785.

It is an arithmetic number, because the mean of its divisors is an integer number (10663028785).

Almost surely, 2^21326057569 is an apocalyptic number.

It is an amenable number.

21326057569 is a deficient number, since it is larger than the sum of its proper divisors (1).

21326057569 is an equidigital number, since it uses as much as digits as its factorization.

21326057569 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 680400, while the sum is 46.

The spelling of 21326057569 in words is "twenty-one billion, three hundred twenty-six million, fifty-seven thousand, five hundred sixty-nine".