261898 has 16 divisors (see below), whose sum is σ = 483840. Its totient is φ = 103536.

The previous prime is 261887. The next prime is 261917. The reversal of 261898 is 898162.

It is a super-3 number, since 3×261898³ = 53891193337448376, which contains 333 as substring.

It is a zygodrome in base 4.

It is an unprimeable number.

261898 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 538 + ... + 901.

It is an arithmetic number, because the mean of its divisors is an integer number (30240).

261898 is a Friedman number, since it can be written as 9+8^6-2^8+1, using all its digits and the basic arithmetic operations.

2²⁶¹⁸⁹⁸ is an apocalyptic number.

261898 is a deficient number, since it is larger than the sum of its proper divisors (221942).

261898 is a wasteful number, since it uses less digits than its factorization.

261898 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1461.

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

The square root of 261898 is about 511.7597092386. The cubic root of 261898 is about 63.9799742033.

The spelling of 261898 in words is "two hundred sixty-one thousand, eight hundred ninety-eight".