205009818 has 16 divisors (see below), whose sum is σ = 441559776. Its totient is φ = 63079920.

The previous prime is 205009801. The next prime is 205009841. The reversal of 205009818 is 818900502.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1314088 + ... + 1314243.

It is an arithmetic number, because the mean of its divisors is an integer number (27597486).

Almost surely, 2^205009818 is an apocalyptic number.

205009818 is an abundant number, since it is smaller than the sum of its proper divisors (236549958).

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

205009818 is a wasteful number, since it uses less digits than its factorization.

205009818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2628349.

The product of its (nonzero) digits is 5760, while the sum is 33.

The square root of 205009818 is about 14318.1639186035. The cubic root of 205009818 is about 589.6462669437.

The spelling of 205009818 in words is "two hundred five million, nine thousand, eight hundred eighteen".