206689131772878 has 32 divisors (see below), whose sum is σ = 437698482071040. Its totient is φ = 64843078801280.

The previous prime is 206689131772867. The next prime is 206689131772919. The reversal of 206689131772878 is 878277131986602.

It is a super-2 number, since 2×206689131772878² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2815723 + ... + 20525753.

It is an arithmetic number, because the mean of its divisors is an integer number (13678077564720).

Almost surely, 2^{206689131772878} is an apocalyptic number.

206689131772878 is an abundant number, since it is smaller than the sum of its proper divisors (231009350298162).

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

206689131772878 is a wasteful number, since it uses less digits than its factorization.

206689131772878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17824472.

The product of its (nonzero) digits is 682795008, while the sum is 75.

The spelling of 206689131772878 in words is "two hundred six trillion, six hundred eighty-nine billion, one hundred thirty-one million, seven hundred seventy-two thousand, eight hundred seventy-eight".