19900209 has 16 divisors (see below), whose sum is σ = 30549888. Its totient is φ = 11286912.

The previous prime is 19900193. The next prime is 19900253. The reversal of 19900209 is 90200991.

It is not a de Polignac number, because 19900209 - 2⁴ = 19900193 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19900259) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 582 + ... + 6335.

It is an arithmetic number, because the mean of its divisors is an integer number (1909368).

Almost surely, 2^19900209 is an apocalyptic number.

It is an amenable number.

19900209 is a deficient number, since it is larger than the sum of its proper divisors (10649679).

19900209 is a wasteful number, since it uses less digits than its factorization.

19900209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7064.

The product of its (nonzero) digits is 1458, while the sum is 30.

The square root of 19900209 is about 4460.9650301252. The cubic root of 19900209 is about 270.9895513008.

The spelling of 19900209 in words is "nineteen million, nine hundred thousand, two hundred nine".