265637642761 has 2 divisors, whose sum is σ = 265637642762. Its totient is φ = 265637642760.

The previous prime is 265637642749. The next prime is 265637642807. The reversal of 265637642761 is 167246736562.

It is a happy number.

265637642761 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 181105569225 + 84532073536 = 425565^2 + 290744^2 .

It is a cyclic number.

It is not a de Polignac number, because 265637642761 - 2¹³ = 265637634569 is a prime.

It is not a weakly prime, because it can be changed into another prime (265637642731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 132818821380 + 132818821381.

It is an arithmetic number, because the mean of its divisors is an integer number (132818821381).

Almost surely, 2^265637642761 is an apocalyptic number.

It is an amenable number.

265637642761 is a deficient number, since it is larger than the sum of its proper divisors (1).

265637642761 is an equidigital number, since it uses as much as digits as its factorization.

265637642761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15240960, while the sum is 55.

The spelling of 265637642761 in words is "two hundred sixty-five billion, six hundred thirty-seven million, six hundred forty-two thousand, seven hundred sixty-one".