261279 has 8 divisors (see below), whose sum is σ = 387120. Its totient is φ = 174168.

The previous prime is 261271. The next prime is 261281. The reversal of 261279 is 972162.

It is not a de Polignac number, because 261279 - 2³ = 261271 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 9677 = 261279 / (2 + 6 + 1 + 2 + 7 + 9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261271) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4812 + ... + 4865.

It is an arithmetic number, because the mean of its divisors is an integer number (48390).

2²⁶¹²⁷⁹ is an apocalyptic number.

261279 is a deficient number, since it is larger than the sum of its proper divisors (125841).

261279 is an equidigital number, since it uses as much as digits as its factorization.

261279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9686 (or 9680 counting only the distinct ones).

The product of its digits is 1512, while the sum is 27.

The square root of 261279 is about 511.1545754466. The cubic root of 261279 is about 63.9295285510.

The spelling of 261279 in words is "two hundred sixty-one thousand, two hundred seventy-nine".