6440820000 has 120 divisors (see below), whose sum is σ = 21127374576. Its totient is φ = 1717536000.

The previous prime is 6440819977. The next prime is 6440820007. The reversal of 6440820000 is 280446.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (6440820007) by changing a digit.

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 19 ways as a sum of consecutive naturals, for example, 6327 + ... + 113673.

Almost surely, 2^6440820000 is an apocalyptic number.

6440820000 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 6440820000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10563687288).

6440820000 is an abundant number, since it is smaller than the sum of its proper divisors (14686554576).

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

6440820000 is a wasteful number, since it uses less digits than its factorization.

6440820000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107380 (or 107357 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 6440820000 is about 80254.7194873921. The cubic root of 6440820000 is about 1860.5744554684.

The spelling of 6440820000 in words is "six billion, four hundred forty million, eight hundred twenty thousand".