6440986188 has 480 divisors, whose sum is σ = 22220943360. Its totient is φ = 1587237120.

The previous prime is 6440986141. The next prime is 6440986193. The reversal of 6440986188 is 8816890446.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 207773733 + ... + 207773763.

It is an arithmetic number, because the mean of its divisors is an integer number (46293632).

Almost surely, 2^6440986188 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6440986188, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11110471680).

6440986188 is an abundant number, since it is smaller than the sum of its proper divisors (15779957172).

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

6440986188 is a wasteful number, since it uses less digits than its factorization.

6440986188 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111 (or 85 counting only the distinct ones).

The product of its (nonzero) digits is 2654208, while the sum is 54.

The square root of 6440986188 is about 80255.7548590754. The cubic root of 6440986188 is about 1860.5904577004.

The spelling of 6440986188 in words is "six billion, four hundred forty million, nine hundred eighty-six thousand, one hundred eighty-eight".