666944438 has 16 divisors (see below), whose sum is σ = 1005048000. Its totient is φ = 331932936.

The previous prime is 666944431. The next prime is 666944461. The reversal of 666944438 is 834449666.

It is a happy number.

666944438 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666944431) 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, 561281 + ... + 562467.

It is an arithmetic number, because the mean of its divisors is an integer number (62815500).

Almost surely, 2^666944438 is an apocalyptic number.

666944438 is a deficient number, since it is larger than the sum of its proper divisors (338103562).

666944438 is a wasteful number, since it uses less digits than its factorization.

666944438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2251.

The product of its digits is 2985984, while the sum is 50.

The square root of 666944438 is about 25825.2674332716. The cubic root of 666944438 is about 873.7017756947.

The spelling of 666944438 in words is "six hundred sixty-six million, nine hundred forty-four thousand, four hundred thirty-eight".