66889986 has 16 divisors (see below), whose sum is σ = 135777504. Its totient is φ = 21963744.

The previous prime is 66889961. The next prime is 66889987. The reversal of 66889986 is 68998866.

66889986 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×66889986³ (a number of 24 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (66889987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82795 + ... + 83598.

It is an arithmetic number, because the mean of its divisors is an integer number (8486094).

Almost surely, 2^66889986 is an apocalyptic number.

66889986 is an abundant number, since it is smaller than the sum of its proper divisors (68887518).

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

66889986 is a wasteful number, since it uses less digits than its factorization.

66889986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166465.

The product of its digits is 8957952, while the sum is 60.

The square root of 66889986 is about 8178.6298363479. The cubic root of 66889986 is about 405.9323861941.

The spelling of 66889986 in words is "sixty-six million, eight hundred eighty-nine thousand, nine hundred eighty-six".