1320781824 has 144 divisors (see below), whose sum is σ = 3850806960. Its totient is φ = 436101120.

The previous prime is 1320781807. The next prime is 1320781837. The reversal of 1320781824 is 4281870231.

It is a tau number, because it is divible by the number of its divisors (144).

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 (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2414319 + ... + 2414865.

It is an arithmetic number, because the mean of its divisors is an integer number (26741715).

Almost surely, 2^1320781824 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 1320781824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1925403480).

1320781824 is an abundant number, since it is smaller than the sum of its proper divisors (2530025136).

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

1320781824 is a wasteful number, since it uses less digits than its factorization.

1320781824 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 706 (or 683 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 1320781824 is about 36342.5621551371. The cubic root of 1320781824 is about 1097.1778411464.

The spelling of 1320781824 in words is "one billion, three hundred twenty million, seven hundred eighty-one thousand, eight hundred twenty-four".