261166 has 8 divisors (see below), whose sum is σ = 397800. Its totient is φ = 128568.

The previous prime is 261127. The next prime is 261167. The reversal of 261166 is 661162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261167) by changing a digit.

261166 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 3 ways as a sum of consecutive naturals, for example, 841 + ... + 1108.

It is an arithmetic number, because the mean of its divisors is an integer number (49725).

2²⁶¹¹⁶⁶ is an apocalyptic number.

261166 is a deficient number, since it is larger than the sum of its proper divisors (136634).

261166 is a wasteful number, since it uses less digits than its factorization.

261166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2018.

The product of its digits is 432, while the sum is 22.

The square root of 261166 is about 511.0440294143. The cubic root of 261166 is about 63.9203109734.

The spelling of 261166 in words is "two hundred sixty-one thousand, one hundred sixty-six".