209745380 has 96 divisors (see below), whose sum is σ = 499903488. Its totient is φ = 73382400.

The previous prime is 209745353. The next prime is 209745401. The reversal of 209745380 is 83547902.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 426935 + ... + 427425.

It is an arithmetic number, because the mean of its divisors is an integer number (5207328).

Almost surely, 2^209745380 is an apocalyptic number.

209745380 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 209745380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (249951744).

209745380 is an abundant number, since it is smaller than the sum of its proper divisors (290158108).

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

209745380 is a wasteful number, since it uses less digits than its factorization.

209745380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 597 (or 595 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 38.

The square root of 209745380 is about 14482.5888569689. The cubic root of 209745380 is about 594.1518693254.

The spelling of 209745380 in words is "two hundred nine million, seven hundred forty-five thousand, three hundred eighty".