265217261 has 2 divisors, whose sum is σ = 265217262. Its totient is φ = 265217260.

The previous prime is 265217237. The next prime is 265217269. The reversal of 265217261 is 162712562.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 196840900 + 68376361 = 14030^2 + 8269^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-265217261 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (265217269) 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, 132608630 + 132608631.

It is an arithmetic number, because the mean of its divisors is an integer number (132608631).

Almost surely, 2^265217261 is an apocalyptic number.

It is an amenable number.

265217261 is a deficient number, since it is larger than the sum of its proper divisors (1).

265217261 is an equidigital number, since it uses as much as digits as its factorization.

265217261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10080, while the sum is 32.

The square root of 265217261 is about 16285.4923474852. The cubic root of 265217261 is about 642.4913157239.

The spelling of 265217261 in words is "two hundred sixty-five million, two hundred seventeen thousand, two hundred sixty-one".