206121290 has 8 divisors (see below), whose sum is σ = 371018340. Its totient is φ = 82448512.

The previous prime is 206121281. The next prime is 206121301. The reversal of 206121290 is 92121602.

206121290 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 186131449 + 19989841 = 13643^2 + 4471^2 .

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

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 3 ways as a sum of consecutive naturals, for example, 10306055 + ... + 10306074.

Almost surely, 2^206121290 is an apocalyptic number.

206121290 is a deficient number, since it is larger than the sum of its proper divisors (164897050).

206121290 is a wasteful number, since it uses less digits than its factorization.

206121290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20612136.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 206121290 is about 14356.9248100002. The cubic root of 206121290 is about 590.7099468723.

Adding to 206121290 its reverse (92121602), we get a palindrome (298242892).

The spelling of 206121290 in words is "two hundred six million, one hundred twenty-one thousand, two hundred ninety".