16781778756 has 72 divisors (see below), whose sum is σ = 43795874304. Its totient is φ = 5414160960.

The previous prime is 16781778749. The next prime is 16781778763. The reversal of 16781778756 is 65787718761.

16781778756 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 (16781778749) and next prime (16781778763).

It is a junction number, because it is equal to n+sod(n) for n = 16781778693 and 16781778702.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 221431 + ... + 287393.

It is an arithmetic number, because the mean of its divisors is an integer number (608276032).

Almost surely, 2^16781778756 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 16781778756, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21897937152).

16781778756 is an abundant number, since it is smaller than the sum of its proper divisors (27014095548).

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

16781778756 is a wasteful number, since it uses less digits than its factorization.

16781778756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66201 (or 66196 counting only the distinct ones).

The product of its digits is 27659520, while the sum is 63.

The spelling of 16781778756 in words is "sixteen billion, seven hundred eighty-one million, seven hundred seventy-eight thousand, seven hundred fifty-six".