6645279616 has 48 divisors (see below), whose sum is σ = 13533192720. Its totient is φ = 3248851200.

The previous prime is 6645279601. The next prime is 6645279637. The reversal of 6645279616 is 6169725466.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6322291 + ... + 6323341.

It is an arithmetic number, because the mean of its divisors is an integer number (281941515).

Almost surely, 2^6645279616 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 6645279616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6766596360).

6645279616 is an abundant number, since it is smaller than the sum of its proper divisors (6887913104).

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

6645279616 is an frugal number, since it uses more digits than its factorization.

6645279616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2163 (or 1100 counting only the distinct ones).

The product of its digits is 3265920, while the sum is 52.

The square root of 6645279616 is about 81518.5844823130. The cubic root of 6645279616 is about 1880.0573032179.

The spelling of 6645279616 in words is "six billion, six hundred forty-five million, two hundred seventy-nine thousand, six hundred sixteen".