6400309440 has 336 divisors, whose sum is σ = 23767084800. Its totient is φ = 1455003648.

The previous prime is 6400309427. The next prime is 6400309451. The reversal of 6400309440 is 449030046.

It is a tau number, because it is divible by the number of its divisors (336).

It is a super-2 number, since 2×6400309440² = 81927921855506227200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 6400309398 and 6400309407.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 16887171 + ... + 16887549.

Almost surely, 2^6400309440 is an apocalyptic number.

6400309440 is a gapful number since it is divisible by the number (60) 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 6400309440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11883542400).

6400309440 is an abundant number, since it is smaller than the sum of its proper divisors (17366775360).

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

6400309440 is a wasteful number, since it uses less digits than its factorization.

6400309440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 772 (or 755 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 30.

The square root of 6400309440 is about 80001.9339766233. The cubic root of 6400309440 is about 1856.6654557389.

Adding to 6400309440 its reverse (449030046), we get a palindrome (6849339486).

The spelling of 6400309440 in words is "six billion, four hundred million, three hundred nine thousand, four hundred forty".