26064491561 has 2 divisors, whose sum is σ = 26064491562. Its totient is φ = 26064491560.

The previous prime is 26064491543. The next prime is 26064491657. The reversal of 26064491561 is 16519446062.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19960038400 + 6104453161 = 141280^2 + 78131^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-26064491561 is a prime.

It is not a weakly prime, because it can be changed into another prime (26064491861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13032245780 + 13032245781.

It is an arithmetic number, because the mean of its divisors is an integer number (13032245781).

Almost surely, 2^26064491561 is an apocalyptic number.

It is an amenable number.

26064491561 is a deficient number, since it is larger than the sum of its proper divisors (1).

26064491561 is an equidigital number, since it uses as much as digits as its factorization.

26064491561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 311040, while the sum is 44.

The spelling of 26064491561 in words is "twenty-six billion, sixty-four million, four hundred ninety-one thousand, five hundred sixty-one".