206642155 has 8 divisors (see below), whose sum is σ = 248108112. Its totient is φ = 165222048.

The previous prime is 206642153. The next prime is 206642159. The reversal of 206642155 is 551246602.

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

It is a cyclic number.

It is not a de Polignac number, because 206642155 - 2¹ = 206642153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206642153) 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, 609 + ... + 20338.

It is an arithmetic number, because the mean of its divisors is an integer number (31013514).

Almost surely, 2^206642155 is an apocalyptic number.

206642155 is a deficient number, since it is larger than the sum of its proper divisors (41465957).

206642155 is a wasteful number, since it uses less digits than its factorization.

206642155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22925.

The product of its (nonzero) digits is 14400, while the sum is 31.

The square root of 206642155 is about 14375.0532172928. The cubic root of 206642155 is about 591.2070996768.

Adding to 206642155 its reverse (551246602), we get a palindrome (757888757).

The spelling of 206642155 in words is "two hundred six million, six hundred forty-two thousand, one hundred fifty-five".