66668915 has 8 divisors (see below), whose sum is σ = 80062080. Its totient is φ = 53295552.

The previous prime is 66668897. The next prime is 66668923. The reversal of 66668915 is 51986666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66668915 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66668915.

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, 3902 + ... + 12188.

It is an arithmetic number, because the mean of its divisors is an integer number (10007760).

Almost surely, 2^66668915 is an apocalyptic number.

66668915 is a deficient number, since it is larger than the sum of its proper divisors (13393165).

66668915 is a wasteful number, since it uses less digits than its factorization.

66668915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9901.

The product of its digits is 466560, while the sum is 47.

The square root of 66668915 is about 8165.1034898524. The cubic root of 66668915 is about 405.4846912595.

The spelling of 66668915 in words is "sixty-six million, six hundred sixty-eight thousand, nine hundred fifteen".