261869 has 4 divisors (see below), whose sum is σ = 264000. Its totient is φ = 259740.

The previous prime is 261847. The next prime is 261881. The reversal of 261869 is 968162.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261869 is a prime.

It is a super-2 number, since 2×261869² = 137150746322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261169) 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, 869 + ... + 1130.

It is an arithmetic number, because the mean of its divisors is an integer number (66000).

2²⁶¹⁸⁶⁹ is an apocalyptic number.

It is an amenable number.

261869 is a deficient number, since it is larger than the sum of its proper divisors (2131).

261869 is a wasteful number, since it uses less digits than its factorization.

261869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2130.

The product of its digits is 5184, while the sum is 32.

The square root of 261869 is about 511.7313748443. The cubic root of 261869 is about 63.9776126124.

The spelling of 261869 in words is "two hundred sixty-one thousand, eight hundred sixty-nine".