81698760757 has 2 divisors, whose sum is σ = 81698760758. Its totient is φ = 81698760756.

The previous prime is 81698760739. The next prime is 81698760817. The reversal of 81698760757 is 75706789618.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 70232420196 + 11466340561 = 265014^2 + 107081^2 .

It is a cyclic number.

It is not a de Polignac number, because 81698760757 - 2¹⁹ = 81698236469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81698760727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40849380378 + 40849380379.

It is an arithmetic number, because the mean of its divisors is an integer number (40849380379).

Almost surely, 2^81698760757 is an apocalyptic number.

It is an amenable number.

81698760757 is a deficient number, since it is larger than the sum of its proper divisors (1).

81698760757 is an equidigital number, since it uses as much as digits as its factorization.

81698760757 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 35562240, while the sum is 64.

The spelling of 81698760757 in words is "eighty-one billion, six hundred ninety-eight million, seven hundred sixty thousand, seven hundred fifty-seven".