260639 has 4 divisors (see below), whose sum is σ = 263424. Its totient is φ = 257856.

The previous prime is 260629. The next prime is 260647. The reversal of 260639 is 936062.

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 260639 - 2¹⁶ = 195103 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (260609) 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, 1247 + ... + 1440.

It is an arithmetic number, because the mean of its divisors is an integer number (65856).

2²⁶⁰⁶³⁹ is an apocalyptic number.

260639 is a deficient number, since it is larger than the sum of its proper divisors (2785).

260639 is an equidigital number, since it uses as much as digits as its factorization.

260639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2784.

The product of its (nonzero) digits is 1944, while the sum is 26.

The square root of 260639 is about 510.5281578914. The cubic root of 260639 is about 63.8772876506.

It can be divided in two parts, 2 and 60639, that multiplied together give a triangular number (121278 = T₄₉₂).

The spelling of 260639 in words is "two hundred sixty thousand, six hundred thirty-nine".