209065920 has 224 divisors, whose sum is σ = 774240768. Its totient is φ = 46804992.

The previous prime is 209065907. The next prime is 209065921. The reversal of 209065920 is 29560902.

It is a tau number, because it is divible by the number of its divisors (224).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209065921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 355867 + ... + 356453.

It is an arithmetic number, because the mean of its divisors is an integer number (3456432).

Almost surely, 2^209065920 is an apocalyptic number.

209065920 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 209065920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (387120384).

209065920 is an abundant number, since it is smaller than the sum of its proper divisors (565174848).

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

209065920 is a wasteful number, since it uses less digits than its factorization.

209065920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 667 (or 657 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 33.

The square root of 209065920 is about 14459.1120059290. The cubic root of 209065920 is about 593.5095998903.

The spelling of 209065920 in words is "two hundred nine million, sixty-five thousand, nine hundred twenty".