264721 has 4 divisors (see below), whose sum is σ = 267444. Its totient is φ = 262000.

The previous prime is 264697. The next prime is 264731. The reversal of 264721 is 127462.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 239121 + 25600 = 489^2 + 160^2 .

It is a cyclic number.

It is not a de Polignac number, because 264721 - 2¹⁷ = 133649 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 264692 and 264701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (264731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1210 + ... + 1411.

It is an arithmetic number, because the mean of its divisors is an integer number (66861).

2²⁶⁴⁷²¹ is an apocalyptic number.

It is an amenable number.

264721 is a deficient number, since it is larger than the sum of its proper divisors (2723).

264721 is a wasteful number, since it uses less digits than its factorization.

264721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2722.

The product of its digits is 672, while the sum is 22.

The square root of 264721 is about 514.5104469299. The cubic root of 264721 is about 64.2090333203.

The spelling of 264721 in words is "two hundred sixty-four thousand, seven hundred twenty-one".