665108647 has 4 divisors (see below), whose sum is σ = 760124176. Its totient is φ = 570093120.

The previous prime is 665108603. The next prime is 665108657. The reversal of 665108647 is 746801566.

It is a happy number.

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 665108647 - 2¹⁹ = 664584359 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665108657) 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, 47507754 + ... + 47507767.

It is an arithmetic number, because the mean of its divisors is an integer number (190031044).

Almost surely, 2^665108647 is an apocalyptic number.

665108647 is a deficient number, since it is larger than the sum of its proper divisors (95015529).

665108647 is an equidigital number, since it uses as much as digits as its factorization.

665108647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95015528.

The product of its (nonzero) digits is 241920, while the sum is 43.

The square root of 665108647 is about 25789.7004053944. The cubic root of 665108647 is about 872.8994061369.

It can be divided in two parts, 66510 and 8647, that added together give a palindrome (75157).

The spelling of 665108647 in words is "six hundred sixty-five million, one hundred eight thousand, six hundred forty-seven".