666091944 has 64 divisors (see below), whose sum is σ = 2114582400. Its totient is φ = 190311552.

The previous prime is 666091939. The next prime is 666091961. The reversal of 666091944 is 449190666.

666091944 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 666091944.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 218757 + ... + 221780.

It is an arithmetic number, because the mean of its divisors is an integer number (33040350).

Almost surely, 2^666091944 is an apocalyptic number.

It is an amenable number.

666091944 is an abundant number, since it is smaller than the sum of its proper divisors (1448490456).

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

666091944 is a wasteful number, since it uses less digits than its factorization.

666091944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440559 (or 440549 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 45.

The square root of 666091944 is about 25808.7571184666. The cubic root of 666091944 is about 873.3293593174.

The spelling of 666091944 in words is "six hundred sixty-six million, ninety-one thousand, nine hundred forty-four".