209122812 has 72 divisors (see below), whose sum is σ = 540162896. Its totient is φ = 68200704.

The previous prime is 209122801. The next prime is 209122813. The reversal of 209122812 is 218221902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209122813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 667968 + ... + 668280.

Almost surely, 2^209122812 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 209122812, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (270081448).

209122812 is an abundant number, since it is smaller than the sum of its proper divisors (331040084).

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

209122812 is a wasteful number, since it uses less digits than its factorization.

209122812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 667 (or 662 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 209122812 is about 14461.0792128389. The cubic root of 209122812 is about 593.5634312142.

The spelling of 209122812 in words is "two hundred nine million, one hundred twenty-two thousand, eight hundred twelve".