721668770413 has 2 divisors, whose sum is σ = 721668770414. Its totient is φ = 721668770412.

The previous prime is 721668770393. The next prime is 721668770453. The reversal of 721668770413 is 314077866127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 425713186089 + 295955584324 = 652467^2 + 544018^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-721668770413 is a prime.

It is a super-3 number, since 3×721668770413³ (a number of 37 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721668770453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360834385206 + 360834385207.

It is an arithmetic number, because the mean of its divisors is an integer number (360834385207).

Almost surely, 2^721668770413 is an apocalyptic number.

It is an amenable number.

721668770413 is a deficient number, since it is larger than the sum of its proper divisors (1).

721668770413 is an equidigital number, since it uses as much as digits as its factorization.

721668770413 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2370816, while the sum is 52.

The spelling of 721668770413 in words is "seven hundred twenty-one billion, six hundred sixty-eight million, seven hundred seventy thousand, four hundred thirteen".