66561666014 has 4 divisors (see below), whose sum is σ = 99842499024. Its totient is φ = 33280833006.

The previous prime is 66561666011. The next prime is 66561666019. The reversal of 66561666014 is 41066616566.

It is a semiprime because it is the product of two primes.

It is a self number, because there is not a number n which added to its sum of digits gives 66561666014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66561666011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16640416502 + ... + 16640416505.

It is an arithmetic number, because the mean of its divisors is an integer number (24960624756).

Almost surely, 2^66561666014 is an apocalyptic number.

66561666014 is a deficient number, since it is larger than the sum of its proper divisors (33280833010).

66561666014 is a wasteful number, since it uses less digits than its factorization.

66561666014 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33280833009.

The product of its (nonzero) digits is 933120, while the sum is 47.

The spelling of 66561666014 in words is "sixty-six billion, five hundred sixty-one million, six hundred sixty-six thousand, fourteen".