26685665781641 has 2 divisors, whose sum is σ = 26685665781642. Its totient is φ = 26685665781640.

The previous prime is 26685665781637. The next prime is 26685665781727. The reversal of 26685665781641 is 14618756658662.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17942975887225 + 8742689894416 = 4235915^2 + 2956804^2 .

It is a cyclic number.

It is not a de Polignac number, because 26685665781641 - 2² = 26685665781637 is a prime.

It is not a weakly prime, because it can be changed into another prime (26685665781601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13342832890820 + 13342832890821.

It is an arithmetic number, because the mean of its divisors is an integer number (13342832890821).

Almost surely, 2^{26685665781641} is an apocalyptic number.

It is an amenable number.

26685665781641 is a deficient number, since it is larger than the sum of its proper divisors (1).

26685665781641 is an equidigital number, since it uses as much as digits as its factorization.

26685665781641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 696729600, while the sum is 71.

The spelling of 26685665781641 in words is "twenty-six trillion, six hundred eighty-five billion, six hundred sixty-five million, seven hundred eighty-one thousand, six hundred forty-one".