16621994188800 has 5670 divisors, whose sum is σ = 85254651171459. Its totient is φ = 3188234649600.

The previous prime is 16621994188783. The next prime is 16621994188831. The reversal of 16621994188800 is 888149912661.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

16621994188800 is a `hidden beast` number, since 166 + 219 + 9 + 4 + 188 + 80 + 0 = 666.

It can be written as a sum of positive squares in 5 ways, for example, as 1040595849216 + 15581398339584 = 1020096^2 + 3947328^2 .

It is a tau number, because it is divible by the number of its divisors (5670).

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=2882880.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 404 ways as a sum of consecutive naturals, for example, 1278614937594 + ... + 1278614937606.

Almost surely, 2^{16621994188800} is an apocalyptic number.

16621994188800 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 16621994188800

16621994188800 is an abundant number, since it is smaller than the sum of its proper divisors (68632656982659).

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

16621994188800 is a wasteful number, since it uses less digits than its factorization.

16621994188800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110 (or 41 counting only the distinct ones).

The product of its (nonzero) digits is 11943936, while the sum is 63.

The spelling of 16621994188800 in words is "sixteen trillion, six hundred twenty-one billion, nine hundred ninety-four million, one hundred eighty-eight thousand, eight hundred".