665683521734813 has 4 divisors (see below), whose sum is σ = 665683574159328. Its totient is φ = 665683469310300.

The previous prime is 665683521734773. The next prime is 665683521734821. The reversal of 665683521734813 is 318437125386566.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 665683521734813 - 2¹⁶ = 665683521669277 is a prime.

It is a super-2 number, since 2×665683521734813² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665683521730813) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6167288 + ... + 37005438.

It is an arithmetic number, because the mean of its divisors is an integer number (166420893539832).

Almost surely, 2^{665683521734813} is an apocalyptic number.

It is an amenable number.

665683521734813 is a deficient number, since it is larger than the sum of its proper divisors (52424515).

665683521734813 is a wasteful number, since it uses less digits than its factorization.

665683521734813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52424514.

The product of its digits is 522547200, while the sum is 68.

The spelling of 665683521734813 in words is "six hundred sixty-five trillion, six hundred eighty-three billion, five hundred twenty-one million, seven hundred thirty-four thousand, eight hundred thirteen".