1304432640 has 416 divisors, whose sum is σ = 5315631360. Its totient is φ = 297271296.

The previous prime is 1304432639. The next prime is 1304432651. The reversal of 1304432640 is 462344031.

1304432640 is a `hidden beast` number, since 13 + 0 + 4 + 4 + 3 + 2 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3870552 + ... + 3870888.

It is an arithmetic number, because the mean of its divisors is an integer number (12777960).

Almost surely, 2^1304432640 is an apocalyptic number.

1304432640 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 1304432640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2657815680).

1304432640 is an abundant number, since it is smaller than the sum of its proper divisors (4011198720).

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

1304432640 is an equidigital number, since it uses as much as digits as its factorization.

1304432640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 382 (or 354 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

The square root of 1304432640 is about 36116.9301021003. The cubic root of 1304432640 is about 1092.6319250295.

Adding to 1304432640 its reverse (462344031), we get a palindrome (1766776671).

The spelling of 1304432640 in words is "one billion, three hundred four million, four hundred thirty-two thousand, six hundred forty".