816440 has 16 divisors (see below), whose sum is σ = 1837080. Its totient is φ = 326560.

The previous prime is 816427. The next prime is 816443. The reversal of 816440 is 44618.

It is a happy number.

816440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a plaindrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816443) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10166 + ... + 10245.

2⁸¹⁶⁴⁴⁰ is an apocalyptic number.

It is an amenable number.

816440 is an abundant number, since it is smaller than the sum of its proper divisors (1020640).

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

816440 is a wasteful number, since it uses less digits than its factorization.

816440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20422 (or 20418 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 816440 is about 903.5706945226. The cubic root of 816440 is about 93.4633675021.

The spelling of 816440 in words is "eight hundred sixteen thousand, four hundred forty".