665809147 has 2 divisors, whose sum is σ = 665809148. Its totient is φ = 665809146.

The previous prime is 665809141. The next prime is 665809181. The reversal of 665809147 is 741908566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 665809147 - 2¹¹ = 665807099 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 665809097 and 665809106.

It is not a weakly prime, because it can be changed into another prime (665809141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332904573 + 332904574.

It is an arithmetic number, because the mean of its divisors is an integer number (332904574).

Almost surely, 2^665809147 is an apocalyptic number.

665809147 is a deficient number, since it is larger than the sum of its proper divisors (1).

665809147 is an equidigital number, since it uses as much as digits as its factorization.

665809147 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 362880, while the sum is 46.

The square root of 665809147 is about 25803.2778344148. The cubic root of 665809147 is about 873.2057478123.

The spelling of 665809147 in words is "six hundred sixty-five million, eight hundred nine thousand, one hundred forty-seven".