681517451199973 has 2 divisors, whose sum is σ = 681517451199974. Its totient is φ = 681517451199972.

The previous prime is 681517451199953. The next prime is 681517451200031. The reversal of 681517451199973 is 379991154715186.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 681078096985729 + 439354214244 = 26097473^2 + 662838^2 .

It is a cyclic number.

It is not a de Polignac number, because 681517451199973 - 2²⁹ = 681516914329061 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 681517451199973.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (681517451199953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340758725599986 + 340758725599987.

It is an arithmetic number, because the mean of its divisors is an integer number (340758725599987).

Almost surely, 2^{681517451199973} is an apocalyptic number.

It is an amenable number.

681517451199973 is a deficient number, since it is larger than the sum of its proper divisors (1).

681517451199973 is an equidigital number, since it uses as much as digits as its factorization.

681517451199973 is an evil number, because the sum of its binary digits is even.

The product of its digits is 514382400, while the sum is 76.

The spelling of 681517451199973 in words is "six hundred eighty-one trillion, five hundred seventeen billion, four hundred fifty-one million, one hundred ninety-nine thousand, nine hundred seventy-three".