665766707 has 16 divisors (see below), whose sum is σ = 709430400. Its totient is φ = 623016000.

The previous prime is 665766697. The next prime is 665766727. The reversal of 665766707 is 707667566.

It is a cyclic number.

It is not a de Polignac number, because 665766707 - 2⁴ = 665766691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665766727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 652844 + ... + 653862.

It is an arithmetic number, because the mean of its divisors is an integer number (44339400).

Almost surely, 2^665766707 is an apocalyptic number.

665766707 is a deficient number, since it is larger than the sum of its proper divisors (43663693).

665766707 is a wasteful number, since it uses less digits than its factorization.

665766707 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1426.

The product of its (nonzero) digits is 2222640, while the sum is 50.

The square root of 665766707 is about 25802.4554451703. The cubic root of 665766707 is about 873.1871941274.

The spelling of 665766707 in words is "six hundred sixty-five million, seven hundred sixty-six thousand, seven hundred seven".