206661780000 has 720 divisors, whose sum is σ = 820416332736. Its totient is φ = 50855040000.

The previous prime is 206661779977. The next prime is 206661780011. The reversal of 206661780000 is 87166602.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (720).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 63178365 + ... + 63181635.

Almost surely, 2^206661780000 is an apocalyptic number.

206661780000 is a gapful number since it is divisible by the number (20) 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 206661780000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (410208166368).

206661780000 is an abundant number, since it is smaller than the sum of its proper divisors (613754552736).

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

206661780000 is an equidigital number, since it uses as much as digits as its factorization.

206661780000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3329 (or 3294 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The spelling of 206661780000 in words is "two hundred six billion, six hundred sixty-one million, seven hundred eighty thousand".