210721685568 has 224 divisors, whose sum is σ = 601527140352. Its totient is φ = 64912742400.

The previous prime is 210721685519. The next prime is 210721685677. The reversal of 210721685568 is 865586127012.

It is a self number, because there is not a number n which added to its sum of digits gives 210721685568.

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 31 ways as a sum of consecutive naturals, for example, 141139030 + ... + 141140522.

Almost surely, 2^210721685568 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 210721685568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (300763570176).

210721685568 is an abundant number, since it is smaller than the sum of its proper divisors (390805454784).

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

210721685568 is a wasteful number, since it uses less digits than its factorization.

210721685568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2593 (or 2583 counting only the distinct ones).

The product of its (nonzero) digits is 1612800, while the sum is 51.

The spelling of 210721685568 in words is "two hundred ten billion, seven hundred twenty-one million, six hundred eighty-five thousand, five hundred sixty-eight".