1328539440 has 80 divisors (see below), whose sum is σ = 4124736000. Its totient is φ = 353738496.

The previous prime is 1328539439. The next prime is 1328539543. The reversal of 1328539440 is 449358231.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 168711 + ... + 176409.

It is an arithmetic number, because the mean of its divisors is an integer number (51559200).

Almost surely, 2^1328539440 is an apocalyptic number.

1328539440 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 1328539440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2062368000).

1328539440 is an abundant number, since it is smaller than the sum of its proper divisors (2796196560).

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

1328539440 is a wasteful number, since it uses less digits than its factorization.

1328539440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8434 (or 8428 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 39.

The square root of 1328539440 is about 36449.1349691594. The cubic root of 1328539440 is about 1099.3217416525.

It can be divided in two parts, 13285 and 39440, that added together give a palindrome (52725).

The spelling of 1328539440 in words is "one billion, three hundred twenty-eight million, five hundred thirty-nine thousand, four hundred forty".