66666664 has 16 divisors (see below), whose sum is σ = 125100000. Its totient is φ = 33306672.

The previous prime is 66666653. The next prime is 66666667. The reversal of 66666664 is 46666666.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (66666667) 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, 10837 + ... + 15835.

It is an arithmetic number, because the mean of its divisors is an integer number (7818750).

Almost surely, 2^66666664 is an apocalyptic number.

It is an amenable number.

66666664 is a deficient number, since it is larger than the sum of its proper divisors (58433336).

66666664 is a wasteful number, since it uses less digits than its factorization.

66666664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6672 (or 6668 counting only the distinct ones).

The product of its digits is 1119744, while the sum is 46.

The square root of 66666664 is about 8164.9656459779. The cubic root of 66666664 is about 405.4801276318.

It can be divided in two parts, 666666 and 64, that multiplied together give a palindrome (42666624).

The spelling of 66666664 in words is "sixty-six million, six hundred sixty-six thousand, six hundred sixty-four".