26400391265 has 4 divisors (see below), whose sum is σ = 31680469524. Its totient is φ = 21120313008.

The previous prime is 26400391223. The next prime is 26400391267. The reversal of 26400391265 is 56219300462.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7589720161 + 18810671104 = 87119^2 + 137152^2 .

It is a cyclic number.

It is not a de Polignac number, because 26400391265 - 2¹⁰ = 26400390241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (26400391267) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2640039122 + ... + 2640039131.

It is an arithmetic number, because the mean of its divisors is an integer number (7920117381).

Almost surely, 2^26400391265 is an apocalyptic number.

It is an amenable number.

26400391265 is a deficient number, since it is larger than the sum of its proper divisors (5280078259).

26400391265 is an equidigital number, since it uses as much as digits as its factorization.

26400391265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5280078258.

The product of its (nonzero) digits is 77760, while the sum is 38.

The spelling of 26400391265 in words is "twenty-six billion, four hundred million, three hundred ninety-one thousand, two hundred sixty-five".