6640501980 has 96 divisors (see below), whose sum is σ = 21309281280. Its totient is φ = 1513566720.

The previous prime is 6640501961. The next prime is 6640501993. The reversal of 6640501980 is 891050466.

It is a congruent number.

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, 128760 + ... + 172800.

It is an arithmetic number, because the mean of its divisors is an integer number (221971680).

Almost surely, 2^6640501980 is an apocalyptic number.

6640501980 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 6640501980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10654640640).

6640501980 is an abundant number, since it is smaller than the sum of its proper divisors (14668779300).

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

6640501980 is a wasteful number, since it uses less digits than its factorization.

6640501980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44419 (or 44417 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 39.

The square root of 6640501980 is about 81489.2752452738. The cubic root of 6640501980 is about 1879.6066383134.

The spelling of 6640501980 in words is "six billion, six hundred forty million, five hundred one thousand, nine hundred eighty".