20688935696641 has 2 divisors, whose sum is σ = 20688935696642. Its totient is φ = 20688935696640.

The previous prime is 20688935696579. The next prime is 20688935696677. The reversal of 20688935696641 is 14669653988602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14526228746241 + 6162706950400 = 3811329^2 + 2482480^2 .

It is a cyclic number.

It is not a de Polignac number, because 20688935696641 - 2¹⁷ = 20688935565569 is a prime.

It is not a weakly prime, because it can be changed into another prime (20688935696041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10344467848320 + 10344467848321.

It is an arithmetic number, because the mean of its divisors is an integer number (10344467848321).

Almost surely, 2^{20688935696641} is an apocalyptic number.

It is an amenable number.

20688935696641 is a deficient number, since it is larger than the sum of its proper divisors (1).

20688935696641 is an equidigital number, since it uses as much as digits as its factorization.

20688935696641 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 806215680, while the sum is 73.

The spelling of 20688935696641 in words is "twenty trillion, six hundred eighty-eight billion, nine hundred thirty-five million, six hundred ninety-six thousand, six hundred forty-one".