265016561 has 2 divisors, whose sum is σ = 265016562. Its totient is φ = 265016560.

The previous prime is 265016539. The next prime is 265016569. The reversal of 265016561 is 165610562.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 206784400 + 58232161 = 14380^2 + 7631^2 .

It is a cyclic number.

It is not a de Polignac number, because 265016561 - 2²² = 260822257 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (265016569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 132508280 + 132508281.

It is an arithmetic number, because the mean of its divisors is an integer number (132508281).

Almost surely, 2^265016561 is an apocalyptic number.

It is an amenable number.

265016561 is a deficient number, since it is larger than the sum of its proper divisors (1).

265016561 is an equidigital number, since it uses as much as digits as its factorization.

265016561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 265016561 is about 16279.3292552242. The cubic root of 265016561 is about 642.3292089454.

The spelling of 265016561 in words is "two hundred sixty-five million, sixteen thousand, five hundred sixty-one".