6640189920 has 1152 divisors, whose sum is σ = 30888345600. Its totient is φ = 1316818944.

The previous prime is 6640189873. The next prime is 6640189951. The reversal of 6640189920 is 299810466.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 52284897 + ... + 52285023.

It is an arithmetic number, because the mean of its divisors is an integer number (26812800).

Almost surely, 2^6640189920 is an apocalyptic number.

6640189920 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 6640189920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15444172800).

6640189920 is an abundant number, since it is smaller than the sum of its proper divisors (24248155680).

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

6640189920 is a wasteful number, since it uses less digits than its factorization.

6640189920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197 (or 176 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 45.

The square root of 6640189920 is about 81487.3604922874. The cubic root of 6640189920 is about 1879.5771947945.

The spelling of 6640189920 in words is "six billion, six hundred forty million, one hundred eighty-nine thousand, nine hundred twenty".