666666444 has 24 divisors (see below), whose sum is σ = 1597598128. Its totient is φ = 216216000.

The previous prime is 666666421. The next prime is 666666457. The reversal of 666666444 is 444666666.

It is a nude number because it is divisible by every one of its digits.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 666666393 and 666666402.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 750307 + ... + 751194.

Almost surely, 2^666666444 is an apocalyptic number.

It is an amenable number.

666666444 is an abundant number, since it is smaller than the sum of its proper divisors (930931684).

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

666666444 is a wasteful number, since it uses less digits than its factorization.

666666444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1501545 (or 1501543 counting only the distinct ones).

The product of its digits is 2985984, while the sum is 48.

The square root of 666666444 is about 25819.8846627943. The cubic root of 666666444 is about 873.5803674777.

The spelling of 666666444 in words is "six hundred sixty-six million, six hundred sixty-six thousand, four hundred forty-four".