816817840 has 20 divisors (see below), whose sum is σ = 1899101664. Its totient is φ = 326727104.

The previous prime is 816817831. The next prime is 816817843. The reversal of 816817840 is 48718618.

816817840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (816817843) 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, 5105032 + ... + 5105191.

Almost surely, 2^816817840 is an apocalyptic number.

816817840 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

816817840 is an abundant number, since it is smaller than the sum of its proper divisors (1082283824).

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

816817840 is a wasteful number, since it uses less digits than its factorization.

816817840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10210236 (or 10210230 counting only the distinct ones).

The product of its (nonzero) digits is 86016, while the sum is 43.

The square root of 816817840 is about 28580.0251924312. The cubic root of 816817840 is about 934.7778323889. Note that the first 3 decimals are identical.

The spelling of 816817840 in words is "eight hundred sixteen million, eight hundred seventeen thousand, eight hundred forty".