261143 has 4 divisors (see below), whose sum is σ = 263568. Its totient is φ = 258720.

The previous prime is 261127. The next prime is 261167. The reversal of 261143 is 341162.

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

It is a cyclic number.

It is not a de Polignac number, because 261143 - 2⁴ = 261127 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261043) 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, 1043 + ... + 1268.

It is an arithmetic number, because the mean of its divisors is an integer number (65892).

2²⁶¹¹⁴³ is an apocalyptic number.

261143 is a deficient number, since it is larger than the sum of its proper divisors (2425).

261143 is a wasteful number, since it uses less digits than its factorization.

261143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2424.

The product of its digits is 144, while the sum is 17.

The square root of 261143 is about 511.0215259654. The cubic root of 261143 is about 63.9184345036.

It can be divided in two parts, 261 and 143, that added together give a palindrome (404).

The spelling of 261143 in words is "two hundred sixty-one thousand, one hundred forty-three".