265009773681 has 45 divisors (see below), whose sum is σ = 404813594779. Its totient is φ = 172772096256.

The previous prime is 265009773673. The next prime is 265009773701. The reversal of 265009773681 is 186377900562.

The square root of 265009773681 is 514791.

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

265009773681 is a `hidden beast` number, since 2 + 6 + 500 + 9 + 7 + 73 + 68 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 88932186225 + 176077587456 = 298215^2 + 419616^2 .

It is not a de Polignac number, because 265009773681 - 2³ = 265009773673 is a prime.

It is a super-2 number, since 2×265009773681² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (265009773641) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 217755985 + ... + 217757201.

Almost surely, 2^265009773681 is an apocalyptic number.

265009773681 is the 514791-st square number.

265009773681 is the 257396-th centered octagonal number.

It is an amenable number.

265009773681 is a deficient number, since it is larger than the sum of its proper divisors (139803821098).

265009773681 is an frugal number, since it uses more digits than its factorization.

265009773681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2540 (or 1267 counting only the distinct ones).

The product of its (nonzero) digits is 3810240, while the sum is 54.

The spelling of 265009773681 in words is "two hundred sixty-five billion, nine million, seven hundred seventy-three thousand, six hundred eighty-one".