209538168 has 64 divisors (see below), whose sum is σ = 603313920. Its totient is φ = 59404800.

The previous prime is 209538103. The next prime is 209538169. The reversal of 209538168 is 861835902.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209538169) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17248 + ... + 26768.

It is an arithmetic number, because the mean of its divisors is an integer number (9426780).

Almost surely, 2^209538168 is an apocalyptic number.

209538168 is a gapful number since it is divisible by the number (28) 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 209538168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (301656960).

209538168 is an abundant number, since it is smaller than the sum of its proper divisors (393775752).

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

209538168 is a wasteful number, since it uses less digits than its factorization.

209538168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9668 (or 9664 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 42.

The square root of 209538168 is about 14475.4332577647. The cubic root of 209538168 is about 593.9561463617.

The spelling of 209538168 in words is "two hundred nine million, five hundred thirty-eight thousand, one hundred sixty-eight".