261969 has 4 divisors (see below), whose sum is σ = 349296. Its totient is φ = 174644.

The previous prime is 261959. The next prime is 261971. The reversal of 261969 is 969162.

It is a happy number.

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 not a de Polignac number, because 261969 - 2⁸ = 261713 is a prime.

It is a super-2 number, since 2×261969² = 137255513922, which contains 22 as substring.

It is a D-number.

It is a nialpdrome in base 8.

It is not an unprimeable number, because it can be changed into a prime (261959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43659 + ... + 43664.

It is an arithmetic number, because the mean of its divisors is an integer number (87324).

2²⁶¹⁹⁶⁹ is an apocalyptic number.

It is an amenable number.

261969 is a deficient number, since it is larger than the sum of its proper divisors (87327).

261969 is an equidigital number, since it uses as much as digits as its factorization.

261969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87326.

The product of its digits is 5832, while the sum is 33.

The square root of 261969 is about 511.8290730312. The cubic root of 261969 is about 63.9857552933.

The spelling of 261969 in words is "two hundred sixty-one thousand, nine hundred sixty-nine".