206991138816 has 1008 divisors, whose sum is σ = 794571830208. Its totient is φ = 50429952000.

The previous prime is 206991138791. The next prime is 206991138857. The reversal of 206991138816 is 618831199602.

It is a tau number, because it is divible by the number of its divisors (1008).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2049417166 + ... + 2049417266.

Almost surely, 2^206991138816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 206991138816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (397285915104).

206991138816 is an abundant number, since it is smaller than the sum of its proper divisors (587580691392).

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

206991138816 is a wasteful number, since it uses less digits than its factorization.

206991138816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189 (or 143 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 54.

The spelling of 206991138816 in words is "two hundred six billion, nine hundred ninety-one million, one hundred thirty-eight thousand, eight hundred sixteen".