265399098561 has 15 divisors (see below), whose sum is σ = 396467308083. Its totient is φ = 176929641360.

The previous prime is 265399098551. The next prime is 265399098581. The reversal of 265399098561 is 165890993562.

The square root of 265399098561 is 515169.

It is a perfect power (a square), and thus also a powerful number.

265399098561 is a `hidden beast` number, since 2 + 6 + 539 + 9 + 0 + 98 + 5 + 6 + 1 = 666.

265399098561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 54718098561 + 210681000000 = 233919^2 + 459000^2 .

It is not a de Polignac number, because 265399098561 - 2⁹ = 265399098049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (265399098511) 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 in 14 ways as a sum of consecutive naturals, for example, 4607901 + ... + 4665141.

Almost surely, 2^265399098561 is an apocalyptic number.

265399098561 is the 515169-th square number.

265399098561 is the 257585-th centered octagonal number.

It is an amenable number.

265399098561 is a deficient number, since it is larger than the sum of its proper divisors (131068209522).

265399098561 is an frugal number, since it uses more digits than its factorization.

265399098561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114494 (or 57244 counting only the distinct ones).

The product of its (nonzero) digits is 31492800, while the sum is 63.

The spelling of 265399098561 in words is "two hundred sixty-five billion, three hundred ninety-nine million, ninety-eight thousand, five hundred sixty-one".