66663668 has 12 divisors (see below), whose sum is σ = 116847360. Its totient is φ = 33278712.

The previous prime is 66663661. The next prime is 66663689. The reversal of 66663668 is 86636666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66663661) 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, 10388 + ... + 15531.

It is an arithmetic number, because the mean of its divisors is an integer number (9737280).

Almost surely, 2^66663668 is an apocalyptic number.

It is an amenable number.

66663668 is a deficient number, since it is larger than the sum of its proper divisors (50183692).

66663668 is a wasteful number, since it uses less digits than its factorization.

66663668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26566 (or 26564 counting only the distinct ones).

The product of its digits is 1119744, while the sum is 47.

The square root of 66663668 is about 8164.7821771312. The cubic root of 66663668 is about 405.4740534483.

The spelling of 66663668 in words is "sixty-six million, six hundred sixty-three thousand, six hundred sixty-eight".