It is a happy number.
It is a congruent number.
Almost surely, 21323120366 is an apocalyptic number.
It is a practical number, because each smaller number is the sum of distinct divisors of 1323120366, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1554220800).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
1323120366 is a wasteful number, since it uses less digits than its factorization.
1323120366 is an evil number, because the sum of its binary digits is even.
The square root of 1323120366 is about 36374.7215247072. The cubic root of 1323120366 is about 1097.8250042113.
Adding to 1323120366 its reverse (6630213231), we get a palindrome (7953333597).
The spelling of 1323120366 in words is "one billion, three hundred twenty-three million, one hundred twenty thousand, three hundred sixty-six".