205802090 has 16 divisors (see below), whose sum is σ = 398939688. Its totient is φ = 75988416.

The previous prime is 205802081. The next prime is 205802117. The reversal of 205802090 is 90208502.

It can be written as a sum of positive squares in 4 ways, for example, as 189585361 + 16216729 = 13769^2 + 4027^2 .

It is a Harshad number since it is a multiple of its sum of digits (26).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 791417 + ... + 791676.

Almost surely, 2^205802090 is an apocalyptic number.

205802090 is a deficient number, since it is larger than the sum of its proper divisors (193137598).

205802090 is a wasteful number, since it uses less digits than its factorization.

205802090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1583113.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 205802090 is about 14345.8039161282. The cubic root of 205802090 is about 590.4048643147.

The spelling of 205802090 in words is "two hundred five million, eight hundred two thousand, ninety".