261679 has 4 divisors (see below), whose sum is σ = 285480. Its totient is φ = 237880.

The previous prime is 261673. The next prime is 261697. The reversal of 261679 is 976162.

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 261679 - 2⁹ = 261167 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261679.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261673) 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, 11884 + ... + 11905.

It is an arithmetic number, because the mean of its divisors is an integer number (71370).

2²⁶¹⁶⁷⁹ is an apocalyptic number.

261679 is a deficient number, since it is larger than the sum of its proper divisors (23801).

261679 is a wasteful number, since it uses less digits than its factorization.

261679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23800.

The product of its digits is 4536, while the sum is 31.

The square root of 261679 is about 511.5456968835. The cubic root of 261679 is about 63.9621358060.

The spelling of 261679 in words is "two hundred sixty-one thousand, six hundred seventy-nine".