206456647878 has 128 divisors (see below), whose sum is σ = 522818150400. Its totient is φ = 59865868800.

The previous prime is 206456647823. The next prime is 206456647889. The reversal of 206456647878 is 878746654602.

206456647878 is a `hidden beast` number, since 2 + 0 + 64 + 566 + 4 + 7 + 8 + 7 + 8 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2507038 + ... + 2588078.

It is an arithmetic number, because the mean of its divisors is an integer number (4084516800).

Almost surely, 2^206456647878 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 206456647878, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (261409075200).

206456647878 is an abundant number, since it is smaller than the sum of its proper divisors (316361502522).

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

206456647878 is a wasteful number, since it uses less digits than its factorization.

206456647878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81275 (or 81269 counting only the distinct ones).

The product of its (nonzero) digits is 108380160, while the sum is 63.

The spelling of 206456647878 in words is "two hundred six billion, four hundred fifty-six million, six hundred forty-seven thousand, eight hundred seventy-eight".