26640646247 has 2 divisors, whose sum is σ = 26640646248. Its totient is φ = 26640646246.

The previous prime is 26640646237. The next prime is 26640646289. The reversal of 26640646247 is 74264604662.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 26640646247 - 2¹² = 26640642151 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26640646237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13320323123 + 13320323124.

It is an arithmetic number, because the mean of its divisors is an integer number (13320323124).

Almost surely, 2^26640646247 is an apocalyptic number.

26640646247 is a deficient number, since it is larger than the sum of its proper divisors (1).

26640646247 is an equidigital number, since it uses as much as digits as its factorization.

26640646247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2322432, while the sum is 47.

The spelling of 26640646247 in words is "twenty-six billion, six hundred forty million, six hundred forty-six thousand, two hundred forty-seven".