66706980 has 72 divisors (see below), whose sum is σ = 198464448. Its totient is φ = 16737792.

The previous prime is 66706979. The next prime is 66706987. The reversal of 66706980 is 8960766.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (66706987) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15417 + ... + 19263.

Almost surely, 2^66706980 is an apocalyptic number.

66706980 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 66706980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99232224).

66706980 is an abundant number, since it is smaller than the sum of its proper divisors (131757468).

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

66706980 is a wasteful number, since it uses less digits than its factorization.

66706980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3893 (or 3874 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 42.

The square root of 66706980 is about 8167.4341136002. The cubic root of 66706980 is about 405.5618478483.

The spelling of 66706980 in words is "sixty-six million, seven hundred six thousand, nine hundred eighty".