43521320000 has 140 divisors (see below), whose sum is σ = 108234838140. Its totient is φ = 17357568000.

The previous prime is 43521319981. The next prime is 43521320021. The reversal of 43521320000 is 2312534.

It is a happy number.

It can be written as a sum of positive squares in 10 ways, for example, as 33976811584 + 9544508416 = 184328^2 + 97696^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 15558602 + ... + 15561398.

Almost surely, 2^43521320000 is an apocalyptic number.

43521320000 is a gapful number since it is divisible by the number (40) 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 43521320000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (54117419070).

43521320000 is an abundant number, since it is smaller than the sum of its proper divisors (64713518140).

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

43521320000 is an equidigital number, since it uses as much as digits as its factorization.

43521320000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3218 (or 3193 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 20.

Adding to 43521320000 its reverse (2312534), we get a palindrome (43523632534).

The spelling of 43521320000 in words is "forty-three billion, five hundred twenty-one million, three hundred twenty thousand".