665301649 has 2 divisors, whose sum is σ = 665301650. Its totient is φ = 665301648.

The previous prime is 665301631. The next prime is 665301653. The reversal of 665301649 is 946103566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 446054400 + 219247249 = 21120^2 + 14807^2 .

It is a cyclic number.

It is not a de Polignac number, because 665301649 - 2⁷ = 665301521 is a prime.

It is not a weakly prime, because it can be changed into another prime (665301149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332650824 + 332650825.

It is an arithmetic number, because the mean of its divisors is an integer number (332650825).

Almost surely, 2^665301649 is an apocalyptic number.

It is an amenable number.

665301649 is a deficient number, since it is larger than the sum of its proper divisors (1).

665301649 is an equidigital number, since it uses as much as digits as its factorization.

665301649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 116640, while the sum is 40.

The square root of 665301649 is about 25793.4419765955. The cubic root of 665301649 is about 872.9838309592.

The spelling of 665301649 in words is "six hundred sixty-five million, three hundred one thousand, six hundred forty-nine".