209214881915856 has 160 divisors (see below), whose sum is σ = 567458080358400. Its totient is φ = 66342971358720.

The previous prime is 209214881915839. The next prime is 209214881915857. The reversal of 209214881915856 is 658519188412902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209214881915857) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15519955 + ... + 25676813.

It is an arithmetic number, because the mean of its divisors is an integer number (3546613002240).

Almost surely, 2^{209214881915856} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 209214881915856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (283729040179200).

209214881915856 is an abundant number, since it is smaller than the sum of its proper divisors (358243198442544).

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

209214881915856 is a wasteful number, since it uses less digits than its factorization.

209214881915856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10157137 (or 10157131 counting only the distinct ones).

The product of its (nonzero) digits is 99532800, while the sum is 69.

The spelling of 209214881915856 in words is "two hundred nine trillion, two hundred fourteen billion, eight hundred eighty-one million, nine hundred fifteen thousand, eight hundred fifty-six".