864520 has 16 divisors (see below), whose sum is σ = 1945260. Its totient is φ = 345792.

The previous prime is 864511. The next prime is 864533. The reversal of 864520 is 25468.

It can be written as a sum of positive squares in 2 ways, for example, as 784996 + 79524 = 886^2 + 282^2 .

It is a super-3 number, since 3×864520³ = 1938413336332224000, which contains 333 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10767 + ... + 10846.

2⁸⁶⁴⁵²⁰ is an apocalyptic number.

It is an amenable number.

864520 is an abundant number, since it is smaller than the sum of its proper divisors (1080740).

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

864520 is a wasteful number, since it uses less digits than its factorization.

864520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21624 (or 21620 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 864520 is about 929.7956764795. The cubic root of 864520 is about 95.2631668913.

Adding to 864520 its reverse (25468), we get a palindrome (889988).

The spelling of 864520 in words is "eight hundred sixty-four thousand, five hundred twenty".