261123 has 4 divisors (see below), whose sum is σ = 348168. Its totient is φ = 174080.

The previous prime is 261101. The next prime is 261127. The reversal of 261123 is 321162.

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 261123 - 2⁶ = 261059 is a prime.

It is a super-2 number, since 2×261123² = 136370442258, which contains 22 as substring.

It is a D-number.

It is a zygodrome in base 2.

It is not an unprimeable number, because it can be changed into a prime (261127) 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, 43518 + ... + 43523.

It is an arithmetic number, because the mean of its divisors is an integer number (87042).

2²⁶¹¹²³ is an apocalyptic number.

261123 is a deficient number, since it is larger than the sum of its proper divisors (87045).

261123 is an equidigital number, since it uses as much as digits as its factorization.

261123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87044.

The product of its digits is 72, while the sum is 15.

The square root of 261123 is about 511.0019569434. The cubic root of 261123 is about 63.9168027012.

Adding to 261123 its reverse (321162), we get a palindrome (582285).

The spelling of 261123 in words is "two hundred sixty-one thousand, one hundred twenty-three".