265180661 has 4 divisors (see below), whose sum is σ = 271648524. Its totient is φ = 258712800.

The previous prime is 265180631. The next prime is 265180679. The reversal of 265180661 is 166081562.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 166081562 = 2 ⋅83040781.

It can be written as a sum of positive squares in 2 ways, for example, as 18879025 + 246301636 = 4345^2 + 15694^2 .

It is a cyclic number.

It is not a de Polignac number, because 265180661 - 2¹⁸ = 264918517 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (265180631) 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 3 ways as a sum of consecutive naturals, for example, 3233870 + ... + 3233951.

It is an arithmetic number, because the mean of its divisors is an integer number (67912131).

Almost surely, 2^265180661 is an apocalyptic number.

It is an amenable number.

265180661 is a deficient number, since it is larger than the sum of its proper divisors (6467863).

265180661 is an equidigital number, since it uses as much as digits as its factorization.

265180661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6467862.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 265180661 is about 16284.3686091908. The cubic root of 265180661 is about 642.4617597492.

Subtracting from 265180661 its reverse (166081562), we obtain a palindrome (99099099).

The spelling of 265180661 in words is "two hundred sixty-five million, one hundred eighty thousand, six hundred sixty-one".