6649918128 has 160 divisors (see below), whose sum is σ = 22518558720. Its totient is φ = 1838661120.

The previous prime is 6649918087. The next prime is 6649918139. The reversal of 6649918128 is 8218199466.

It is a super-2 number, since 2×6649918128² = 88442822218206048768, which contains 22 as substring.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

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

It is a nude number because it is divisible by every one of its digits.

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, 58276 + ... + 129212.

It is an arithmetic number, because the mean of its divisors is an integer number (140740992).

Almost surely, 2^6649918128 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 6649918128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11259279360).

6649918128 is an abundant number, since it is smaller than the sum of its proper divisors (15868640592).

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

6649918128 is a wasteful number, since it uses less digits than its factorization.

6649918128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70992 (or 70980 counting only the distinct ones).

The product of its digits is 1492992, while the sum is 54.

The square root of 6649918128 is about 81547.0301605153. The cubic root of 6649918128 is about 1880.4946382184.

The spelling of 6649918128 in words is "six billion, six hundred forty-nine million, nine hundred eighteen thousand, one hundred twenty-eight".