16661790720000 has 1620 divisors, whose sum is σ = 64473093580896. Its totient is φ = 4299816960000.

The previous prime is 16661790719953. The next prime is 16661790720019. The reversal of 16661790720000 is 2709716661.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (1620).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 89 ways as a sum of consecutive naturals, for example, 537477119985 + ... + 537477120015.

Almost surely, 2^{16661790720000} is an apocalyptic number.

16661790720000 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 16661790720000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32236546790448).

16661790720000 is an abundant number, since it is smaller than the sum of its proper divisors (47811302860896).

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

16661790720000 is an frugal number, since it uses more digits than its factorization.

16661790720000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109 (or 41 counting only the distinct ones).

The product of its (nonzero) digits is 190512, while the sum is 45.

The spelling of 16661790720000 in words is "sixteen trillion, six hundred sixty-one billion, seven hundred ninety million, seven hundred twenty thousand".