209394581808 has 40 divisors (see below), whose sum is σ = 540953376768. Its totient is φ = 69795952192.

The previous prime is 209394581783. The next prime is 209394581839. The reversal of 209394581808 is 808185493902.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2195041 + ... + 2288447.

Almost surely, 2^209394581808 is an apocalyptic number.

It is an amenable number.

209394581808 is an abundant number, since it is smaller than the sum of its proper divisors (331558794960).

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

209394581808 is a wasteful number, since it uses less digits than its factorization.

209394581808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140121 (or 140115 counting only the distinct ones).

The product of its (nonzero) digits is 4976640, while the sum is 57.

The spelling of 209394581808 in words is "two hundred nine billion, three hundred ninety-four million, five hundred eighty-one thousand, eight hundred eight".