66613666 has 16 divisors (see below), whose sum is σ = 114327360. Its totient is φ = 28515600.

The previous prime is 66613649. The next prime is 66613693. The reversal of 66613666 is 66631666.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12741 + ... + 17191.

It is an arithmetic number, because the mean of its divisors is an integer number (7145460).

Almost surely, 2^66613666 is an apocalyptic number.

66613666 is a deficient number, since it is larger than the sum of its proper divisors (47713694).

66613666 is a wasteful number, since it uses less digits than its factorization.

66613666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5529.

The product of its digits is 139968, while the sum is 40.

The square root of 66613666 is about 8161.7195492127. The cubic root of 66613666 is about 405.3726509632.

The spelling of 66613666 in words is "sixty-six million, six hundred thirteen thousand, six hundred sixty-six".