666444707 has 4 divisors (see below), whose sum is σ = 677740440. Its totient is φ = 655148976.

The previous prime is 666444697. The next prime is 666444719. The reversal of 666444707 is 707444666.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 666444707 - 2¹⁶ = 666379171 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666444787) 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, 5647778 + ... + 5647895.

It is an arithmetic number, because the mean of its divisors is an integer number (169435110).

Almost surely, 2^666444707 is an apocalyptic number.

666444707 is a deficient number, since it is larger than the sum of its proper divisors (11295733).

666444707 is a wasteful number, since it uses less digits than its factorization.

666444707 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11295732.

The product of its (nonzero) digits is 677376, while the sum is 44.

The square root of 666444707 is about 25815.5903864312. The cubic root of 666444707 is about 873.4835041605.

The spelling of 666444707 in words is "six hundred sixty-six million, four hundred forty-four thousand, seven hundred seven".