666777384 has 192 divisors, whose sum is σ = 2240784000. Its totient is φ = 174417408.

The previous prime is 666777379. The next prime is 666777389. The reversal of 666777384 is 483777666.

It is an interprime number because it is at equal distance from previous prime (666777379) and next prime (666777389).

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

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

Its product of digits (7112448) is a multiple of the sum of its prime factors (864).

It is a self number, because there is not a number n which added to its sum of digits gives 666777384.

It is not an unprimeable number, because it can be changed into a prime (666777389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 975907 + ... + 976589.

It is an arithmetic number, because the mean of its divisors is an integer number (11670750).

Almost surely, 2^666777384 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666777384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1120392000).

666777384 is an abundant number, since it is smaller than the sum of its proper divisors (1574006616).

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

666777384 is a wasteful number, since it uses less digits than its factorization.

666777384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 864 (or 857 counting only the distinct ones).

The product of its digits is 7112448, while the sum is 54.

The square root of 666777384 is about 25822.0329176461. The cubic root of 666777384 is about 873.6288223091.

The spelling of 666777384 in words is "six hundred sixty-six million, seven hundred seventy-seven thousand, three hundred eighty-four".