1321888320 has 168 divisors, whose sum is σ = 4565913144. Its totient is φ = 351019008.

The previous prime is 1321888319. The next prime is 1321888343. The reversal of 1321888320 is 238881231.

1321888320 is a `hidden beast` number, since 1 + 321 + 8 + 8 + 8 + 320 = 666.

1321888320 is nontrivially palindromic in base 7.

It can be written as a sum of positive squares in 4 ways, for example, as 3326976 + 1318561344 = 1824^2 + 36312^2 .

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

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 796932 + ... + 798588.

Almost surely, 2^1321888320 is an apocalyptic number.

1321888320 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 1321888320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2282956572).

1321888320 is an abundant number, since it is smaller than the sum of its proper divisors (3244024824).

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

1321888320 is a wasteful number, since it uses less digits than its factorization.

1321888320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1957 (or 1944 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 1321888320 is about 36357.7821105743. The cubic root of 1321888320 is about 1097.4841455914.

The spelling of 1321888320 in words is "one billion, three hundred twenty-one million, eight hundred eighty-eight thousand, three hundred twenty".