816520 has 32 divisors (see below), whose sum is σ = 1863000. Its totient is φ = 322048.

The previous prime is 816499. The next prime is 816521. The reversal of 816520 is 25618.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 527076 + 289444 = 726^2 + 538^2 .

It is a junction number, because it is equal to n+sod(n) for n = 816491 and 816500.

It is not an unprimeable number, because it can be changed into a prime (816521) 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, 5406 + ... + 5554.

2⁸¹⁶⁵²⁰ is an apocalyptic number.

It is an amenable number.

816520 is an abundant number, since it is smaller than the sum of its proper divisors (1046480).

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

816520 is a wasteful number, since it uses less digits than its factorization.

816520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 297 (or 293 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 816520 is about 903.6149622489. The cubic root of 816520 is about 93.4664201147.

The spelling of 816520 in words is "eight hundred sixteen thousand, five hundred twenty".