209208990 has 32 divisors (see below), whose sum is σ = 505437696. Its totient is φ = 55418400.

The previous prime is 209208971. The next prime is 209209003. The reversal of 209208990 is 99802902.

209208990 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18562 + ... + 27621.

It is an arithmetic number, because the mean of its divisors is an integer number (15794928).

Almost surely, 2^209208990 is an apocalyptic number.

209208990 is an abundant number, since it is smaller than the sum of its proper divisors (296228706).

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

209208990 is a wasteful number, since it uses less digits than its factorization.

209208990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46344.

The product of its (nonzero) digits is 23328, while the sum is 39.

The square root of 209208990 is about 14464.0585590629. The cubic root of 209208990 is about 593.6449544175.

The spelling of 209208990 in words is "two hundred nine million, two hundred eight thousand, nine hundred ninety".