16661981448 has 512 divisors, whose sum is σ = 58834944000. Its totient is φ = 4259692800.

The previous prime is 16661981447. The next prime is 16661981459. The reversal of 16661981448 is 84418916661.

It is a super-3 number, since 3×16661981448³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 16661981394 and 16661981403.

It is not an unprimeable number, because it can be changed into a prime (16661981443) by changing a digit.

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 127 ways as a sum of consecutive naturals, for example, 99772261 + ... + 99772427.

It is an arithmetic number, because the mean of its divisors is an integer number (114912000).

Almost surely, 2^16661981448 is an apocalyptic number.

16661981448 is a gapful number since it is divisible by the number (18) 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 16661981448, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29417472000).

16661981448 is an abundant number, since it is smaller than the sum of its proper divisors (42172962552).

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

16661981448 is a wasteful number, since it uses less digits than its factorization.

16661981448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 382 (or 372 counting only the distinct ones).

The product of its digits is 1990656, while the sum is 54.

The spelling of 16661981448 in words is "sixteen billion, six hundred sixty-one million, nine hundred eighty-one thousand, four hundred forty-eight".