209145198 has 16 divisors (see below), whose sum is σ = 440305920. Its totient is φ = 66045816.

The previous prime is 209145161. The next prime is 209145221. The reversal of 209145198 is 891541902.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 917190 + ... + 917417.

It is an arithmetic number, because the mean of its divisors is an integer number (27519120).

Almost surely, 2^209145198 is an apocalyptic number.

209145198 is an abundant number, since it is smaller than the sum of its proper divisors (231160722).

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

209145198 is a wasteful number, since it uses less digits than its factorization.

209145198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1834631.

The product of its (nonzero) digits is 25920, while the sum is 39.

The square root of 209145198 is about 14461.8532007485. The cubic root of 209145198 is about 593.5846102155.

The spelling of 209145198 in words is "two hundred nine million, one hundred forty-five thousand, one hundred ninety-eight".