265403561 has 2 divisors, whose sum is σ = 265403562. Its totient is φ = 265403560.

The previous prime is 265403531. The next prime is 265403569. The reversal of 265403561 is 165304562.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 232410025 + 32993536 = 15245^2 + 5744^2 .

It is a cyclic number.

It is not a de Polignac number, because 265403561 - 2¹⁸ = 265141417 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (265403569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 132701780 + 132701781.

It is an arithmetic number, because the mean of its divisors is an integer number (132701781).

Almost surely, 2^265403561 is an apocalyptic number.

It is an amenable number.

265403561 is a deficient number, since it is larger than the sum of its proper divisors (1).

265403561 is an equidigital number, since it uses as much as digits as its factorization.

265403561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21600, while the sum is 32.

The square root of 265403561 is about 16291.2111581675. The cubic root of 265403561 is about 642.6417183486.

The spelling of 265403561 in words is "two hundred sixty-five million, four hundred three thousand, five hundred sixty-one".