816840 has 48 divisors (see below), whose sum is σ = 2655900. Its totient is φ = 217728.

The previous prime is 816839. The next prime is 816841. The reversal of 816840 is 48618.

816840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (816839) and next prime (816841).

It can be written as a sum of positive squares in 2 ways, for example, as 715716 + 101124 = 846^2 + 318^2 .

It is not an unprimeable number, because it can be changed into a prime (816841) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 775 + ... + 1494.

2⁸¹⁶⁸⁴⁰ is an apocalyptic number.

It is an amenable number.

816840 is an abundant number, since it is smaller than the sum of its proper divisors (1839060).

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

816840 is a wasteful number, since it uses less digits than its factorization.

816840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2286 (or 2279 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 816840 is about 903.7920114717. The cubic root of 816840 is about 93.4786285718.

The spelling of 816840 in words is "eight hundred sixteen thousand, eight hundred forty".