264640 has 28 divisors (see below), whose sum is σ = 630936. Its totient is φ = 105728.

The previous prime is 264637. The next prime is 264643. The reversal of 264640 is 46462.

It is an interprime number because it is at equal distance from previous prime (264637) and next prime (264643).

It is a d-powerful number, because it can be written as 2¹¹ + 6³ + 6³ + 4² + 4⁹ + 0 .

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (264643) 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, 94 + ... + 733.

2²⁶⁴⁶⁴⁰ is an apocalyptic number.

264640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

264640 is an abundant number, since it is smaller than the sum of its proper divisors (366296).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

264640 is an equidigital number, since it uses as much as digits as its factorization.

264640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 844 (or 834 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 264640 is about 514.4317253047. The cubic root of 264640 is about 64.2024837049.

The spelling of 264640 in words is "two hundred sixty-four thousand, six hundred forty".