66839860 has 12 divisors (see below), whose sum is σ = 140363748. Its totient is φ = 26735936.

The previous prime is 66839849. The next prime is 66839873. The reversal of 66839860 is 6893866.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 10679824 + 56160036 = 3268^2 + 7494^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 66839860.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1670977 + ... + 1671016.

It is an arithmetic number, because the mean of its divisors is an integer number (11696979).

Almost surely, 2^66839860 is an apocalyptic number.

It is an amenable number.

66839860 is an abundant number, since it is smaller than the sum of its proper divisors (73523888).

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

66839860 is a wasteful number, since it uses less digits than its factorization.

66839860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3342002 (or 3342000 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 46.

The square root of 66839860 is about 8175.5648122928. The cubic root of 66839860 is about 405.8309616867.

The spelling of 66839860 in words is "sixty-six million, eight hundred thirty-nine thousand, eight hundred sixty".