1328725840 has 40 divisors (see below), whose sum is σ = 3326927688. Its totient is φ = 490606080.

The previous prime is 1328725837. The next prime is 1328725877. The reversal of 1328725840 is 485278231.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 15968016 + 1312757824 = 3996^2 + 36232^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 1328725793 and 1328725802.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 637771 + ... + 639850.

Almost surely, 2^1328725840 is an apocalyptic number.

1328725840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1328725840 is an abundant number, since it is smaller than the sum of its proper divisors (1998201848).

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

1328725840 is a wasteful number, since it uses less digits than its factorization.

1328725840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1277647 (or 1277641 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 40.

The square root of 1328725840 is about 36451.6918674566. The cubic root of 1328725840 is about 1099.3731524935.

The spelling of 1328725840 in words is "one billion, three hundred twenty-eight million, seven hundred twenty-five thousand, eight hundred forty".