816978543744 has 256 divisors, whose sum is σ = 2396567813760. Its totient is φ = 244536115200.

The previous prime is 816978543707. The next prime is 816978543791. The reversal of 816978543744 is 447345879618.

816978543744 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 114724504 + ... + 114731624.

Almost surely, 2^816978543744 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 816978543744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1198283906880).

816978543744 is an abundant number, since it is smaller than the sum of its proper divisors (1579589270016).

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

816978543744 is a wasteful number, since it uses less digits than its factorization.

816978543744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7479 (or 7467 counting only the distinct ones).

The product of its digits is 162570240, while the sum is 66.

The spelling of 816978543744 in words is "eight hundred sixteen billion, nine hundred seventy-eight million, five hundred forty-three thousand, seven hundred forty-four".