26697568643 has 2 divisors, whose sum is σ = 26697568644. Its totient is φ = 26697568642.

The previous prime is 26697568589. The next prime is 26697568673. The reversal of 26697568643 is 34686579662.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 26697568643 - 2¹⁰ = 26697567619 is a prime.

It is a super-2 number, since 2×26697568643² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (26697568673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13348784321 + 13348784322.

It is an arithmetic number, because the mean of its divisors is an integer number (13348784322).

Almost surely, 2^26697568643 is an apocalyptic number.

26697568643 is a deficient number, since it is larger than the sum of its proper divisors (1).

26697568643 is an equidigital number, since it uses as much as digits as its factorization.

26697568643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 78382080, while the sum is 62.

The spelling of 26697568643 in words is "twenty-six billion, six hundred ninety-seven million, five hundred sixty-eight thousand, six hundred forty-three".