209628420 has 48 divisors (see below), whose sum is σ = 590502528. Its totient is φ = 55563520.

The previous prime is 209628407. The next prime is 209628431. The reversal of 209628420 is 24826902.

209628420 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 441 + ... + 20480.

It is an arithmetic number, because the mean of its divisors is an integer number (12302136).

Almost surely, 2^209628420 is an apocalyptic number.

209628420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 209628420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (295251264).

209628420 is an abundant number, since it is smaller than the sum of its proper divisors (380874108).

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

209628420 is a wasteful number, since it uses less digits than its factorization.

209628420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21100 (or 21098 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 209628420 is about 14478.5503417987. The cubic root of 209628420 is about 594.0414101208.

The spelling of 209628420 in words is "two hundred nine million, six hundred twenty-eight thousand, four hundred twenty".