681938065253 has 2 divisors, whose sum is σ = 681938065254. Its totient is φ = 681938065252.

The previous prime is 681938065247. The next prime is 681938065339. The reversal of 681938065253 is 352560839186.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 640843477729 + 41094587524 = 800527^2 + 202718^2 .

It is a cyclic number.

It is not a de Polignac number, because 681938065253 - 2¹⁰ = 681938064229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (681938067253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340969032626 + 340969032627.

It is an arithmetic number, because the mean of its divisors is an integer number (340969032627).

Almost surely, 2^681938065253 is an apocalyptic number.

It is an amenable number.

681938065253 is a deficient number, since it is larger than the sum of its proper divisors (1).

681938065253 is an equidigital number, since it uses as much as digits as its factorization.

681938065253 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9331200, while the sum is 56.

The spelling of 681938065253 in words is "six hundred eighty-one billion, nine hundred thirty-eight million, sixty-five thousand, two hundred fifty-three".