665464649 has 2 divisors, whose sum is σ = 665464650. Its totient is φ = 665464648.

The previous prime is 665464601. The next prime is 665464651. The reversal of 665464649 is 946464566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 425679424 + 239785225 = 20632^2 + 15485^2 .

It is a cyclic number.

It is not a de Polignac number, because 665464649 - 2²⁴ = 648687433 is a prime.

Together with 665464651, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 665464597 and 665464606.

It is not a weakly prime, because it can be changed into another prime (665464699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332732324 + 332732325.

It is an arithmetic number, because the mean of its divisors is an integer number (332732325).

Almost surely, 2^665464649 is an apocalyptic number.

It is an amenable number.

665464649 is a deficient number, since it is larger than the sum of its proper divisors (1).

665464649 is an equidigital number, since it uses as much as digits as its factorization.

665464649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3732480, while the sum is 50.

The square root of 665464649 is about 25796.6015009730. The cubic root of 665464649 is about 873.0551192965.

The spelling of 665464649 in words is "six hundred sixty-five million, four hundred sixty-four thousand, six hundred forty-nine".