264639 has 8 divisors (see below), whose sum is σ = 373680. Its totient is φ = 166016.

The previous prime is 264637. The next prime is 264643. The reversal of 264639 is 936462.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 264639 - 2¹ = 264637 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (264631) 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, 2544 + ... + 2645.

It is an arithmetic number, because the mean of its divisors is an integer number (46710).

2²⁶⁴⁶³⁹ is an apocalyptic number.

264639 is a deficient number, since it is larger than the sum of its proper divisors (109041).

264639 is a wasteful number, since it uses less digits than its factorization.

264639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5209.

The product of its digits is 7776, while the sum is 30.

The square root of 264639 is about 514.4307533575. The cubic root of 264639 is about 64.2024028371.

It can be divided in two parts, 264 and 639, that added together give a triangular number (903 = T₄₂).

The spelling of 264639 in words is "two hundred sixty-four thousand, six hundred thirty-nine".