816680640 has 112 divisors (see below), whose sum is σ = 2656332000. Its totient is φ = 212459520.

The previous prime is 816680587. The next prime is 816680651. The reversal of 816680640 is 46086618.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28986 + ... + 49734.

It is an arithmetic number, because the mean of its divisors is an integer number (23717250).

Almost surely, 2^816680640 is an apocalyptic number.

816680640 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 816680640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1328166000).

816680640 is an abundant number, since it is smaller than the sum of its proper divisors (1839651360).

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

816680640 is a wasteful number, since it uses less digits than its factorization.

816680640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20810 (or 20800 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 39.

The square root of 816680640 is about 28577.6248138294. The cubic root of 816680640 is about 934.7254915879.

The spelling of 816680640 in words is "eight hundred sixteen million, six hundred eighty thousand, six hundred forty".