265633660561 has 2 divisors, whose sum is σ = 265633660562. Its totient is φ = 265633660560.

The previous prime is 265633660489. The next prime is 265633660619. The reversal of 265633660561 is 165066336562.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 192006094225 + 73627566336 = 438185^2 + 271344^2 .

It is a cyclic number.

It is not a de Polignac number, because 265633660561 - 2²⁷ = 265499442833 is a prime.

It is a super-2 number, since 2×265633660561² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (265633660261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 132816830280 + 132816830281.

It is an arithmetic number, because the mean of its divisors is an integer number (132816830281).

Almost surely, 2^265633660561 is an apocalyptic number.

It is an amenable number.

265633660561 is a deficient number, since it is larger than the sum of its proper divisors (1).

265633660561 is an equidigital number, since it uses as much as digits as its factorization.

265633660561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3499200, while the sum is 49.

The spelling of 265633660561 in words is "two hundred sixty-five billion, six hundred thirty-three million, six hundred sixty thousand, five hundred sixty-one".