261800089 has 4 divisors (see below), whose sum is σ = 261851940. Its totient is φ = 261748240.

The previous prime is 261800059. The next prime is 261800093. The reversal of 261800089 is 980008162.

261800089 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 136539225 + 125260864 = 11685^2 + 11192^2 .

It is a cyclic number.

It is not a de Polignac number, because 261800089 - 2⁵ = 261800057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261800009) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17422 + ... + 28759.

It is an arithmetic number, because the mean of its divisors is an integer number (65462985).

Almost surely, 2^261800089 is an apocalyptic number.

It is an amenable number.

261800089 is a deficient number, since it is larger than the sum of its proper divisors (51851).

261800089 is an equidigital number, since it uses as much as digits as its factorization.

261800089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51850.

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 261800089 is about 16180.2376064136. The cubic root of 261800089 is about 639.7200020314.

The spelling of 261800089 in words is "two hundred sixty-one million, eight hundred thousand, eighty-nine".