208921728 has 64 divisors (see below), whose sum is σ = 558021600. Its totient is φ = 69255168.

The previous prime is 208921711. The next prime is 208921729. The reversal of 208921728 is 827129802.

208921728 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (208921729) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72703 + ... + 75521.

Almost surely, 2^208921728 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 208921728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (279010800).

208921728 is an abundant number, since it is smaller than the sum of its proper divisors (349099872).

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

208921728 is a wasteful number, since it uses less digits than its factorization.

208921728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3029 (or 3017 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 208921728 is about 14454.1249475712. The cubic root of 208921728 is about 593.3731213762.

The spelling of 208921728 in words is "two hundred eight million, nine hundred twenty-one thousand, seven hundred twenty-eight".