16811720640 has 672 divisors, whose sum is σ = 70261154880. Its totient is φ = 3759022080.

The previous prime is 16811720609. The next prime is 16811720641. The reversal of 16811720640 is 4602711861.

It is a happy number.

16811720640 is a `hidden beast` number, since 1 + 6 + 8 + 1 + 1 + 7 + 2 + 0 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 16811720595 and 16811720604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16811720641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 13590102 + ... + 13591338.

It is an arithmetic number, because the mean of its divisors is an integer number (104555290).

Almost surely, 2^16811720640 is an apocalyptic number.

16811720640 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 16811720640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35130577440).

16811720640 is an abundant number, since it is smaller than the sum of its proper divisors (53449434240).

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

16811720640 is a wasteful number, since it uses less digits than its factorization.

16811720640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1298 (or 1271 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The spelling of 16811720640 in words is "sixteen billion, eight hundred eleven million, seven hundred twenty thousand, six hundred forty".