666906408 has 96 divisors (see below), whose sum is σ = 2093420160. Its totient is φ = 187850880.

The previous prime is 666906407. The next prime is 666906419. The reversal of 666906408 is 804609666.

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

It is not an unprimeable number, because it can be changed into a prime (666906407) by changing a digit.

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, 26466 + ... + 45102.

It is an arithmetic number, because the mean of its divisors is an integer number (21806460).

Almost surely, 2^666906408 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 666906408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1046710080).

666906408 is an abundant number, since it is smaller than the sum of its proper divisors (1426513752).

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

666906408 is a wasteful number, since it uses less digits than its factorization.

666906408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18727 (or 18720 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The square root of 666906408 is about 25824.5311283671. The cubic root of 666906408 is about 873.6851688590.

The spelling of 666906408 in words is "six hundred sixty-six million, nine hundred six thousand, four hundred eight".