66845665 has 8 divisors (see below), whose sum is σ = 80340480. Its totient is φ = 53392752.

The previous prime is 66845663. The next prime is 66845687. The reversal of 66845665 is 56654866.

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

It is a cyclic number.

It is not a de Polignac number, because 66845665 - 2¹ = 66845663 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66845663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6849 + ... + 13438.

It is an arithmetic number, because the mean of its divisors is an integer number (10042560).

Almost surely, 2^66845665 is an apocalyptic number.

It is an amenable number.

66845665 is a deficient number, since it is larger than the sum of its proper divisors (13494815).

66845665 is a wasteful number, since it uses less digits than its factorization.

66845665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20951.

The product of its digits is 1036800, while the sum is 46.

The square root of 66845665 is about 8175.9198259278. The cubic root of 66845665 is about 405.8427100682.

The spelling of 66845665 in words is "sixty-six million, eight hundred forty-five thousand, six hundred sixty-five".