261918 has 12 divisors (see below), whose sum is σ = 567528. Its totient is φ = 87300.

The previous prime is 261917. The next prime is 261959. The reversal of 261918 is 819162.

261918 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 261891 and 261900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261917) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7258 + ... + 7293.

It is an arithmetic number, because the mean of its divisors is an integer number (47294).

2²⁶¹⁹¹⁸ is an apocalyptic number.

261918 is an abundant number, since it is smaller than the sum of its proper divisors (305610).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261918 is a wasteful number, since it uses less digits than its factorization.

261918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14559 (or 14556 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 261918 is about 511.7792492863. The cubic root of 261918 is about 63.9816027850.

The spelling of 261918 in words is "two hundred sixty-one thousand, nine hundred eighteen".