261180289 has 4 divisors (see below), whose sum is σ = 274926640. Its totient is φ = 247433940.

The previous prime is 261180287. The next prime is 261180319. The reversal of 261180289 is 982081162.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 982081162 = 2 ⋅491040581.

It is a cyclic number.

It is not a de Polignac number, because 261180289 - 2¹ = 261180287 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261180281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6873147 + ... + 6873184.

It is an arithmetic number, because the mean of its divisors is an integer number (68731660).

Almost surely, 2^261180289 is an apocalyptic number.

It is an amenable number.

261180289 is a deficient number, since it is larger than the sum of its proper divisors (13746351).

261180289 is a wasteful number, since it uses less digits than its factorization.

261180289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13746350.

The product of its (nonzero) digits is 13824, while the sum is 37.

The square root of 261180289 is about 16161.0732626271. The cubic root of 261180289 is about 639.2147669511.

The spelling of 261180289 in words is "two hundred sixty-one million, one hundred eighty thousand, two hundred eighty-nine".