265645546561 has 2 divisors, whose sum is σ = 265645546562. Its totient is φ = 265645546560.

The previous prime is 265645546553. The next prime is 265645546567. The reversal of 265645546561 is 165645546562.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 261059683600 + 4585862961 = 510940^2 + 67719^2 .

It is a cyclic number.

It is not a de Polignac number, because 265645546561 - 2³ = 265645546553 is a prime.

It is not a weakly prime, because it can be changed into another prime (265645546567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 132822773280 + 132822773281.

It is an arithmetic number, because the mean of its divisors is an integer number (132822773281).

Almost surely, 2^265645546561 is an apocalyptic number.

It is an amenable number.

265645546561 is a deficient number, since it is larger than the sum of its proper divisors (1).

265645546561 is an equidigital number, since it uses as much as digits as its factorization.

265645546561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920000, while the sum is 55.

Subtracting from 265645546561 its reverse (165645546562), we obtain a palindrome (99999999999).

The spelling of 265645546561 in words is "two hundred sixty-five billion, six hundred forty-five million, five hundred forty-six thousand, five hundred sixty-one".