209490 has 16 divisors (see below), whose sum is σ = 502848. Its totient is φ = 55856.

The previous prime is 209477. The next prime is 209497. The reversal of 209490 is 94902.

209490 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a nialpdrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 209490.

It is not an unprimeable number, because it can be changed into a prime (209497) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3462 + ... + 3521.

It is an arithmetic number, because the mean of its divisors is an integer number (31428).

2²⁰⁹⁴⁹⁰ is an apocalyptic number.

209490 is an abundant number, since it is smaller than the sum of its proper divisors (293358).

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

209490 is a wasteful number, since it uses less digits than its factorization.

209490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6993.

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 209490 is about 457.7007756166. The cubic root of 209490 is about 59.3910630593.

The spelling of 209490 in words is "two hundred nine thousand, four hundred ninety".