261897 has 4 divisors (see below), whose sum is σ = 349200. Its totient is φ = 174596.

The previous prime is 261887. The next prime is 261917. The reversal of 261897 is 798162.

261897 is digitally balanced in base 7, 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 261897 - 2⁴ = 261881 is a prime.

It is an Ulam number.

It is a D-number.

261897 is strictly pandigital in base 7.

It is a nialpdrome in base 8.

It is not an unprimeable number, because it can be changed into a prime (261847) 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, 43647 + ... + 43652.

It is an arithmetic number, because the mean of its divisors is an integer number (87300).

261897 is a Friedman number, since it can be written as 9+8^6-2^(7+1), using all its digits and the basic arithmetic operations.

2²⁶¹⁸⁹⁷ is an apocalyptic number.

It is an amenable number.

261897 is a deficient number, since it is larger than the sum of its proper divisors (87303).

261897 is an equidigital number, since it uses as much as digits as its factorization.

261897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87302.

The product of its digits is 6048, while the sum is 33.

The square root of 261897 is about 511.7587322167. The cubic root of 261897 is about 63.9798927720.

The spelling of 261897 in words is "two hundred sixty-one thousand, eight hundred ninety-seven".