209912659872 has 144 divisors (see below), whose sum is σ = 564136513920. Its totient is φ = 68342450176.

The previous prime is 209912659861. The next prime is 209912659877. The reversal of 209912659872 is 278956219902.

209912659872 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (60) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (209912659877) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 64448068 + ... + 64451324.

It is an arithmetic number, because the mean of its divisors is an integer number (3917614680).

Almost surely, 2^209912659872 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 209912659872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (282068256960).

209912659872 is an abundant number, since it is smaller than the sum of its proper divisors (354223854048).

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

209912659872 is a wasteful number, since it uses less digits than its factorization.

209912659872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3615 (or 3554 counting only the distinct ones).

The product of its (nonzero) digits is 9797760, while the sum is 60.

The spelling of 209912659872 in words is "two hundred nine billion, nine hundred twelve million, six hundred fifty-nine thousand, eight hundred seventy-two".