6649740666 has 12 divisors (see below), whose sum is σ = 14407771482. Its totient is φ = 2216580216.

The previous prime is 6649740641. The next prime is 6649740697. The reversal of 6649740666 is 6660479466.

It can be written as a sum of positive squares in only one way, i.e., 5233799025 + 1415941641 = 72345^2 + 37629^2 .

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, 184715001 + ... + 184715036.

Almost surely, 2^6649740666 is an apocalyptic number.

6649740666 is an abundant number, since it is smaller than the sum of its proper divisors (7758030816).

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

6649740666 is a wasteful number, since it uses less digits than its factorization.

6649740666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369430045 (or 369430042 counting only the distinct ones).

The product of its (nonzero) digits is 7838208, while the sum is 54.

The square root of 6649740666 is about 81545.9420572232. The cubic root of 6649740666 is about 1880.4779102276.

The spelling of 6649740666 in words is "six billion, six hundred forty-nine million, seven hundred forty thousand, six hundred sixty-six".