666085840 has 320 divisors, whose sum is σ = 2019299328. Its totient is φ = 199065600.

The previous prime is 666085837. The next prime is 666085841. The reversal of 666085840 is 48580666.

It is a hoax number, since the sum of its digits (43) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666085841) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 10919410 + ... + 10919470.

Almost surely, 2^666085840 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 666085840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1009649664).

666085840 is an abundant number, since it is smaller than the sum of its proper divisors (1353213488).

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

666085840 is a wasteful number, since it uses less digits than its factorization.

666085840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166 (or 160 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 43.

The square root of 666085840 is about 25808.6388637603. The cubic root of 666085840 is about 873.3266916082.

The spelling of 666085840 in words is "six hundred sixty-six million, eighty-five thousand, eight hundred forty".