66665707 has 8 divisors (see below), whose sum is σ = 70075296. Its totient is φ = 63298752.

The previous prime is 66665701. The next prime is 66665719. The reversal of 66665707 is 70756666.

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 66665707 - 2⁷ = 66665579 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66665701) 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, 7428 + ... + 13729.

It is an arithmetic number, because the mean of its divisors is an integer number (8759412).

Almost surely, 2^66665707 is an apocalyptic number.

66665707 is a deficient number, since it is larger than the sum of its proper divisors (3409589).

66665707 is a wasteful number, since it uses less digits than its factorization.

66665707 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21317.

The product of its (nonzero) digits is 317520, while the sum is 43.

The square root of 66665707 is about 8164.9070417244. The cubic root of 66665707 is about 405.4781874001.

The spelling of 66665707 in words is "sixty-six million, six hundred sixty-five thousand, seven hundred seven".