666005940 has 144 divisors (see below), whose sum is σ = 2232292608. Its totient is φ = 159869952.

The previous prime is 666005903. The next prime is 666006001. The reversal of 666005940 is 49500666.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 666005895 and 666005904.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 65649 + ... + 75111.

It is an arithmetic number, because the mean of its divisors is an integer number (15502032).

Almost surely, 2^666005940 is an apocalyptic number.

666005940 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 666005940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1116146304).

666005940 is an abundant number, since it is smaller than the sum of its proper divisors (1566286668).

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

666005940 is a wasteful number, since it uses less digits than its factorization.

666005940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9518 (or 9513 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 666005940 is about 25807.0908860336. The cubic root of 666005940 is about 873.2917703870.

It can be divided in two parts, 66 and 6005940, that added together give a palindrome (6006006).

The spelling of 666005940 in words is "six hundred sixty-six million, five thousand, nine hundred forty".