209121193830 has 16 divisors (see below), whose sum is σ = 501890865264. Its totient is φ = 55765651680.

The previous prime is 209121193807. The next prime is 209121193871. The reversal of 209121193830 is 38391121902.

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, 3485353201 + ... + 3485353260.

It is an arithmetic number, because the mean of its divisors is an integer number (31368179079).

Almost surely, 2^209121193830 is an apocalyptic number.

209121193830 is an abundant number, since it is smaller than the sum of its proper divisors (292769671434).

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

209121193830 is a wasteful number, since it uses less digits than its factorization.

209121193830 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6970706471.

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

The spelling of 209121193830 in words is "two hundred nine billion, one hundred twenty-one million, one hundred ninety-three thousand, eight hundred thirty".