66861884 has 18 divisors (see below), whose sum is σ = 124298160. Its totient is φ = 31463872.

The previous prime is 66861881. The next prime is 66861911. The reversal of 66861884 is 48816866.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66861881) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 27764 + ... + 30075.

Almost surely, 2^66861884 is an apocalyptic number.

It is an amenable number.

66861884 is a deficient number, since it is larger than the sum of its proper divisors (57436276).

66861884 is a wasteful number, since it uses less digits than its factorization.

66861884 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57877 (or 57858 counting only the distinct ones).

The product of its digits is 442368, while the sum is 47.

The square root of 66861884 is about 8176.9116419343. The cubic root of 66861884 is about 405.8755310977.

The spelling of 66861884 in words is "sixty-six million, eight hundred sixty-one thousand, eight hundred eighty-four".