665152030721 has 2 divisors, whose sum is σ = 665152030722. Its totient is φ = 665152030720.

The previous prime is 665152030717. The next prime is 665152030727. The reversal of 665152030721 is 127030251566.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 458796249025 + 206355781696 = 677345^2 + 454264^2 .

It is a cyclic number.

It is not a de Polignac number, because 665152030721 - 2² = 665152030717 is a prime.

It is not a weakly prime, because it can be changed into another prime (665152030727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332576015360 + 332576015361.

It is an arithmetic number, because the mean of its divisors is an integer number (332576015361).

Almost surely, 2^665152030721 is an apocalyptic number.

It is an amenable number.

665152030721 is a deficient number, since it is larger than the sum of its proper divisors (1).

665152030721 is an equidigital number, since it uses as much as digits as its factorization.

665152030721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 75600, while the sum is 38.

The spelling of 665152030721 in words is "six hundred sixty-five billion, one hundred fifty-two million, thirty thousand, seven hundred twenty-one".