6648636388 has 12 divisors (see below), whose sum is σ = 11642635900. Its totient is φ = 3322168992.

The previous prime is 6648636373. The next prime is 6648636391. The reversal of 6648636388 is 8836368466.

It can be written as a sum of positive squares in 2 ways, for example, as 1394126244 + 5254510144 = 37338^2 + 72488^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 530331 + ... + 542722.

Almost surely, 2^6648636388 is an apocalyptic number.

It is an amenable number.

6648636388 is a deficient number, since it is larger than the sum of its proper divisors (4993999512).

6648636388 is a wasteful number, since it uses less digits than its factorization.

6648636388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1074606 (or 1074604 counting only the distinct ones).

The product of its digits is 23887872, while the sum is 58.

The square root of 6648636388 is about 81539.1708812396. The cubic root of 6648636388 is about 1880.3738116645.

The spelling of 6648636388 in words is "six billion, six hundred forty-eight million, six hundred thirty-six thousand, three hundred eighty-eight".