666643340 has 24 divisors (see below), whose sum is σ = 1527219792. Its totient is φ = 242415680.

The previous prime is 666643333. The next prime is 666643343. The reversal of 666643340 is 43346666.

It is a junction number, because it is equal to n+sod(n) for n = 666643294 and 666643303.

It is not an unprimeable number, because it can be changed into a prime (666643343) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1514879 + ... + 1515318.

It is an arithmetic number, because the mean of its divisors is an integer number (63634158).

Almost surely, 2^666643340 is an apocalyptic number.

It is an amenable number.

666643340 is an abundant number, since it is smaller than the sum of its proper divisors (860576452).

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

666643340 is a wasteful number, since it uses less digits than its factorization.

666643340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3030217 (or 3030215 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 38.

The square root of 666643340 is about 25819.4372518070. The cubic root of 666643340 is about 873.5702757573.

The spelling of 666643340 in words is "six hundred sixty-six million, six hundred forty-three thousand, three hundred forty".