206155566 has 48 divisors (see below), whose sum is σ = 478702224. Its totient is φ = 63889152.

The previous prime is 206155541. The next prime is 206155571. The reversal of 206155566 is 665551602.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 206155566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21340 + ... + 29456.

It is an arithmetic number, because the mean of its divisors is an integer number (9972963).

Almost surely, 2^206155566 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 206155566, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (239351112).

206155566 is an abundant number, since it is smaller than the sum of its proper divisors (272546658).

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

206155566 is a wasteful number, since it uses less digits than its factorization.

206155566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8225 (or 8222 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 36.

The square root of 206155566 is about 14358.1184700503. The cubic root of 206155566 is about 590.7426881965.

The spelling of 206155566 in words is "two hundred six million, one hundred fifty-five thousand, five hundred sixty-six".