66839980 has 24 divisors (see below), whose sum is σ = 140526288. Its totient is φ = 26705088.

The previous prime is 66839959. The next prime is 66839987. The reversal of 66839980 is 8993866.

It is not an unprimeable number, because it can be changed into a prime (66839987) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24862 + ... + 27418.

It is an arithmetic number, because the mean of its divisors is an integer number (5855262).

Almost surely, 2^66839980 is an apocalyptic number.

It is an amenable number.

66839980 is an abundant number, since it is smaller than the sum of its proper divisors (73686308).

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

66839980 is a wasteful number, since it uses less digits than its factorization.

66839980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3873 (or 3871 counting only the distinct ones).

The product of its (nonzero) digits is 559872, while the sum is 49.

The square root of 66839980 is about 8175.5721512320. The cubic root of 66839980 is about 405.8312045542.

The spelling of 66839980 in words is "sixty-six million, eight hundred thirty-nine thousand, nine hundred eighty".