66668940 has 96 divisors (see below), whose sum is σ = 223392960. Its totient is φ = 16409088.

The previous prime is 66668939. The next prime is 66668947. The reversal of 66668940 is 4986666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (66668947) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2272 + ... + 11768.

It is an arithmetic number, because the mean of its divisors is an integer number (2327010).

Almost surely, 2^66668940 is an apocalyptic number.

66668940 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 66668940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111696480).

66668940 is an abundant number, since it is smaller than the sum of its proper divisors (156724020).

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

66668940 is a wasteful number, since it uses less digits than its factorization.

66668940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9528 (or 9520 counting only the distinct ones).

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

The square root of 66668940 is about 8165.1050207575. The cubic root of 66668940 is about 405.4847419434.

The spelling of 66668940 in words is "sixty-six million, six hundred sixty-eight thousand, nine hundred forty".