206620155 has 144 divisors (see below), whose sum is σ = 456468480. Its totient is φ = 84509568.

The previous prime is 206620133. The next prime is 206620181. The reversal of 206620155 is 551026602.

206620155 is a `hidden beast` number, since 20 + 6 + 620 + 15 + 5 = 666.

It is not a de Polignac number, because 206620155 - 2⁵ = 206620123 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 2615406 + ... + 2615484.

It is an arithmetic number, because the mean of its divisors is an integer number (3169920).

Almost surely, 2^206620155 is an apocalyptic number.

206620155 is an abundant number, since it is smaller than the sum of its proper divisors (249848325).

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

206620155 is a wasteful number, since it uses less digits than its factorization.

206620155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158 (or 136 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 206620155 is about 14374.2879823663. The cubic root of 206620155 is about 591.1861181273.

Adding to 206620155 its reverse (551026602), we get a palindrome (757646757).

The spelling of 206620155 in words is "two hundred six million, six hundred twenty thousand, one hundred fifty-five".