666839040 has 288 divisors, whose sum is σ = 2487270240. Its totient is φ = 152076288.

The previous prime is 666839039. The next prime is 666839051. The reversal of 666839040 is 40938666.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 666838983 and 666839001.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1505059 + ... + 1505501.

It is an arithmetic number, because the mean of its divisors is an integer number (8636355).

Almost surely, 2^666839040 is an apocalyptic number.

666839040 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666839040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1243635120).

666839040 is an abundant number, since it is smaller than the sum of its proper divisors (1820431200).

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

666839040 is a wasteful number, since it uses less digits than its factorization.

666839040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 487 (or 460 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 42.

The square root of 666839040 is about 25823.2267542226. The cubic root of 666839040 is about 873.6557492365.

The spelling of 666839040 in words is "six hundred sixty-six million, eight hundred thirty-nine thousand, forty".