66916664 has 8 divisors (see below), whose sum is σ = 125468760. Its totient is φ = 33458328.

The previous prime is 66916657. The next prime is 66916667. The reversal of 66916664 is 46661966.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66916667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4182284 + ... + 4182299.

It is an arithmetic number, because the mean of its divisors is an integer number (15683595).

Almost surely, 2^66916664 is an apocalyptic number.

It is an amenable number.

66916664 is a deficient number, since it is larger than the sum of its proper divisors (58552096).

66916664 is a wasteful number, since it uses less digits than its factorization.

66916664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8364589 (or 8364585 counting only the distinct ones).

The product of its digits is 279936, while the sum is 44.

The square root of 66916664 is about 8180.2606315447. The cubic root of 66916664 is about 405.9863455655.

The spelling of 66916664 in words is "sixty-six million, nine hundred sixteen thousand, six hundred sixty-four".