665513315501 has 2 divisors, whose sum is σ = 665513315502. Its totient is φ = 665513315500.

The previous prime is 665513315497. The next prime is 665513315633. The reversal of 665513315501 is 105513315566.

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., 664634193001 + 879122500 = 815251^2 + 29650^2 .

It is a cyclic number.

It is not a de Polignac number, because 665513315501 - 2² = 665513315497 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665513315101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332756657750 + 332756657751.

It is an arithmetic number, because the mean of its divisors is an integer number (332756657751).

Almost surely, 2^665513315501 is an apocalyptic number.

It is an amenable number.

665513315501 is a deficient number, since it is larger than the sum of its proper divisors (1).

665513315501 is an equidigital number, since it uses as much as digits as its factorization.

665513315501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 202500, while the sum is 41.

The spelling of 665513315501 in words is "six hundred sixty-five billion, five hundred thirteen million, three hundred fifteen thousand, five hundred one".