206605878891 has 8 divisors (see below), whose sum is σ = 275477633424. Its totient is φ = 137735688480.

The previous prime is 206605878859. The next prime is 206605878929. The reversal of 206605878891 is 198878506602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 206605878891 - 2⁵ = 206605878859 is a prime.

It is not an unprimeable number, because it can be changed into a prime (206605878851) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37036 + ... + 643881.

It is an arithmetic number, because the mean of its divisors is an integer number (34434704178).

Almost surely, 2^206605878891 is an apocalyptic number.

206605878891 is a deficient number, since it is larger than the sum of its proper divisors (68871754533).

206605878891 is a wasteful number, since it uses less digits than its factorization.

206605878891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 782061.

The product of its (nonzero) digits is 11612160, while the sum is 60.

The spelling of 206605878891 in words is "two hundred six billion, six hundred five million, eight hundred seventy-eight thousand, eight hundred ninety-one".