16566681400 has 192 divisors, whose sum is σ = 41945752800. Its totient is φ = 6064128000.

The previous prime is 16566681379. The next prime is 16566681403. The reversal of 16566681400 is 418666561.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16566681403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 17604930 + ... + 17605870.

Almost surely, 2^16566681400 is an apocalyptic number.

16566681400 is a gapful number since it is divisible by the number (10) 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 16566681400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20972876400).

16566681400 is an abundant number, since it is smaller than the sum of its proper divisors (25379071400).

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

16566681400 is a wasteful number, since it uses less digits than its factorization.

16566681400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1130 (or 1121 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 43.

The spelling of 16566681400 in words is "sixteen billion, five hundred sixty-six million, six hundred eighty-one thousand, four hundred".