6440006220 has 96 divisors (see below), whose sum is σ = 18788716800. Its totient is φ = 1646125824.

The previous prime is 6440006179. The next prime is 6440006257. The reversal of 6440006220 is 226000446.

It is a super-2 number, since 2×6440006220² = 82947360227277376800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 228547 + ... + 255173.

It is an arithmetic number, because the mean of its divisors is an integer number (195715800).

Almost surely, 2^6440006220 is an apocalyptic number.

6440006220 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 6440006220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9394358400).

6440006220 is an abundant number, since it is smaller than the sum of its proper divisors (12348710580).

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

6440006220 is a wasteful number, since it uses less digits than its factorization.

6440006220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26807 (or 26805 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 6440006220 is about 80249.6493450283. The cubic root of 6440006220 is about 1860.4960926693.

Adding to 6440006220 its reverse (226000446), we get a palindrome (6666006666).

The spelling of 6440006220 in words is "six billion, four hundred forty million, six thousand, two hundred twenty".