6645663360 has 256 divisors, whose sum is σ = 26899603200. Its totient is φ = 1518981120.

The previous prime is 6645663337. The next prime is 6645663379. The reversal of 6645663360 is 633665466.

It is a happy number.

6645663360 is a `hidden beast` number, since 6 + 6 + 4 + 5 + 6 + 633 + 6 + 0 = 666.

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

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, 93490 + ... + 148430.

It is an arithmetic number, because the mean of its divisors is an integer number (105076575).

Almost surely, 2^6645663360 is an apocalyptic number.

6645663360 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 6645663360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13449801600).

6645663360 is an abundant number, since it is smaller than the sum of its proper divisors (20253939840).

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

6645663360 is a wasteful number, since it uses less digits than its factorization.

6645663360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54976 (or 54958 counting only the distinct ones).

The product of its (nonzero) digits is 1399680, while the sum is 45.

The square root of 6645663360 is about 81520.9381692826. The cubic root of 6645663360 is about 1880.0934916536.

The spelling of 6645663360 in words is "six billion, six hundred forty-five million, six hundred sixty-three thousand, three hundred sixty".