265921 has 2 divisors, whose sum is σ = 265922. Its totient is φ = 265920.

The previous prime is 265891. The next prime is 265957. The reversal of 265921 is 129562.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 215296 + 50625 = 464^2 + 225^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-265921 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (265961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 132960 + 132961.

It is an arithmetic number, because the mean of its divisors is an integer number (132961).

2²⁶⁵⁹²¹ is an apocalyptic number.

It is an amenable number.

265921 is a deficient number, since it is larger than the sum of its proper divisors (1).

265921 is an equidigital number, since it uses as much as digits as its factorization.

265921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1080, while the sum is 25.

The square root of 265921 is about 515.6752854268. The cubic root of 265921 is about 64.3059085293.

The spelling of 265921 in words is "two hundred sixty-five thousand, nine hundred twenty-one".