26661011491 has 2 divisors, whose sum is σ = 26661011492. Its totient is φ = 26661011490.

The previous prime is 26661011473. The next prime is 26661011557. The reversal of 26661011491 is 19411016662.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 26661011491 - 2⁵ = 26661011459 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 26661011491.

It is not a weakly prime, because it can be changed into another prime (26661011471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13330505745 + 13330505746.

It is an arithmetic number, because the mean of its divisors is an integer number (13330505746).

Almost surely, 2^26661011491 is an apocalyptic number.

26661011491 is a deficient number, since it is larger than the sum of its proper divisors (1).

26661011491 is an equidigital number, since it uses as much as digits as its factorization.

26661011491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 37.

The spelling of 26661011491 in words is "twenty-six billion, six hundred sixty-one million, eleven thousand, four hundred ninety-one".