6640445220 has 48 divisors (see below), whose sum is σ = 18603623808. Its totient is φ = 1769797120.

The previous prime is 6640445213. The next prime is 6640445249. The reversal of 6640445220 is 225440466.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 80860 + ... + 140780.

It is an arithmetic number, because the mean of its divisors is an integer number (387575496).

Almost surely, 2^6640445220 is an apocalyptic number.

6640445220 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6640445220 is an abundant number, since it is smaller than the sum of its proper divisors (11963178588).

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

6640445220 is a wasteful number, since it uses less digits than its factorization.

6640445220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61780 (or 61778 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 33.

The square root of 6640445220 is about 81488.9269778416. The cubic root of 6640445220 is about 1879.6012829564.

Adding to 6640445220 its reverse (225440466), we get a palindrome (6865885686).

The spelling of 6640445220 in words is "six billion, six hundred forty million, four hundred forty-five thousand, two hundred twenty".