66775812 has 12 divisors (see below), whose sum is σ = 155810256. Its totient is φ = 22258600.

The previous prime is 66775783. The next prime is 66775817. The reversal of 66775812 is 21857766.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (66775817) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2782314 + ... + 2782337.

It is an arithmetic number, because the mean of its divisors is an integer number (12984188).

Almost surely, 2^66775812 is an apocalyptic number.

It is an amenable number.

66775812 is an abundant number, since it is smaller than the sum of its proper divisors (89034444).

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

66775812 is a wasteful number, since it uses less digits than its factorization.

66775812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5564658 (or 5564656 counting only the distinct ones).

The product of its digits is 141120, while the sum is 42.

The square root of 66775812 is about 8171.6468352469. The cubic root of 66775812 is about 405.7012937102.

The spelling of 66775812 in words is "sixty-six million, seven hundred seventy-five thousand, eight hundred twelve".