9726891322657 has 2 divisors, whose sum is σ = 9726891322658. Its totient is φ = 9726891322656.

The previous prime is 9726891322627. The next prime is 9726891322711. The reversal of 9726891322657 is 7562231986279.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5575529897536 + 4151361425121 = 2361256^2 + 2037489^2 .

It is an emirp because it is prime and its reverse (7562231986279) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9726891322657 is a prime.

It is a super-2 number, since 2×9726891322657² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 9726891322592 and 9726891322601.

It is not a weakly prime, because it can be changed into another prime (9726891322607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4863445661328 + 4863445661329.

It is an arithmetic number, because the mean of its divisors is an integer number (4863445661329).

Almost surely, 2^{9726891322657} is an apocalyptic number.

It is an amenable number.

9726891322657 is a deficient number, since it is larger than the sum of its proper divisors (1).

9726891322657 is an equidigital number, since it uses as much as digits as its factorization.

9726891322657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 137168640, while the sum is 67.

The spelling of 9726891322657 in words is "nine trillion, seven hundred twenty-six billion, eight hundred ninety-one million, three hundred twenty-two thousand, six hundred fifty-seven".