265904861 has 2 divisors, whose sum is σ = 265904862. Its totient is φ = 265904860.

The previous prime is 265904833. The next prime is 265904879. The reversal of 265904861 is 168409562.

265904861 = 11530² + 11531².

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 132963961 + 132940900 = 11531^2 + 11530^2 .

It is a cyclic number.

It is not a de Polignac number, because 265904861 - 2²⁶ = 198795997 is a prime.

It is a Sophie Germain 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 (265904801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 132952430 + 132952431.

It is an arithmetic number, because the mean of its divisors is an integer number (132952431).

Almost surely, 2^265904861 is an apocalyptic number.

265904861 is the 11531-st centered square number.

It is an amenable number.

265904861 is a deficient number, since it is larger than the sum of its proper divisors (1).

265904861 is an equidigital number, since it uses as much as digits as its factorization.

265904861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 103680, while the sum is 41.

The square root of 265904861 is about 16306.5894962742. The cubic root of 265904861 is about 643.0460757390.

The spelling of 265904861 in words is "two hundred sixty-five million, nine hundred four thousand, eight hundred sixty-one".