665913671 has 2 divisors, whose sum is σ = 665913672. Its totient is φ = 665913670.

The previous prime is 665913659. The next prime is 665913683. The reversal of 665913671 is 176319566.

It is a balanced prime because it is at equal distance from previous prime (665913659) and next prime (665913683).

It is a cyclic number.

It is not a de Polignac number, because 665913671 - 2¹⁰ = 665912647 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665913071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332956835 + 332956836.

It is an arithmetic number, because the mean of its divisors is an integer number (332956836).

Almost surely, 2^665913671 is an apocalyptic number.

665913671 is a deficient number, since it is larger than the sum of its proper divisors (1).

665913671 is an equidigital number, since it uses as much as digits as its factorization.

665913671 is an evil number, because the sum of its binary digits is even.

The product of its digits is 204120, while the sum is 44.

The square root of 665913671 is about 25805.3031565219. The cubic root of 665913671 is about 873.2514396758.

The spelling of 665913671 in words is "six hundred sixty-five million, nine hundred thirteen thousand, six hundred seventy-one".