1323665280 has 512 divisors, whose sum is σ = 5546188800. Its totient is φ = 291962880.

The previous prime is 1323665251. The next prime is 1323665281. The reversal of 1323665280 is 825663231.

It is a happy number.

1323665280 is a `hidden beast` number, since 13 + 2 + 366 + 5 + 280 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1323665281) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3749584 + ... + 3749936.

It is an arithmetic number, because the mean of its divisors is an integer number (10832400).

Almost surely, 2^1323665280 is an apocalyptic number.

1323665280 is a gapful number since it is divisible by the number (10) 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 1323665280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2773094400).

1323665280 is an abundant number, since it is smaller than the sum of its proper divisors (4222523520).

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

1323665280 is a wasteful number, since it uses less digits than its factorization.

1323665280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 419 (or 401 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 1323665280 is about 36382.2110378135. The cubic root of 1323665280 is about 1097.9756929732.

The spelling of 1323665280 in words is "one billion, three hundred twenty-three million, six hundred sixty-five thousand, two hundred eighty".