6400540800 has 432 divisors, whose sum is σ = 24292618350. Its totient is φ = 1604321280.

The previous prime is 6400540799. The next prime is 6400540831. The reversal of 6400540800 is 80450046.

6400540800 is a `hidden beast` number, since 6 + 40 + 0 + 540 + 80 + 0 = 666.

It can be written as a sum of positive squares in 9 ways, for example, as 1425213504 + 4975327296 = 37752^2 + 70536^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 8322816 + ... + 8323584.

Almost surely, 2^6400540800 is an apocalyptic number.

6400540800 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 6400540800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12146309175).

6400540800 is an abundant number, since it is smaller than the sum of its proper divisors (17892077550).

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

6400540800 is a wasteful number, since it uses less digits than its factorization.

6400540800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 833 (or 796 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 6400540800 is about 80003.3799286005. The cubic root of 6400540800 is about 1856.6878272064.

Adding to 6400540800 its reverse (80450046), we get a palindrome (6480990846).

The spelling of 6400540800 in words is "six billion, four hundred million, five hundred forty thousand, eight hundred".