69681991581857 has 2 divisors, whose sum is σ = 69681991581858. Its totient is φ = 69681991581856.

The previous prime is 69681991581733. The next prime is 69681991581893. The reversal of 69681991581857 is 75818519918696.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57901507364416 + 11780484217441 = 7609304^2 + 3432271^2 .

It is a cyclic number.

It is not a de Polignac number, because 69681991581857 - 2¹⁸ = 69681991319713 is a prime.

It is not a weakly prime, because it can be changed into another prime (69681991580857) 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, 34840995790928 + 34840995790929.

It is an arithmetic number, because the mean of its divisors is an integer number (34840995790929).

Almost surely, 2^{69681991581857} is an apocalyptic number.

It is an amenable number.

69681991581857 is a deficient number, since it is larger than the sum of its proper divisors (1).

69681991581857 is an equidigital number, since it uses as much as digits as its factorization.

69681991581857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2351462400, while the sum is 83.

The spelling of 69681991581857 in words is "sixty-nine trillion, six hundred eighty-one billion, nine hundred ninety-one million, five hundred eighty-one thousand, eight hundred fifty-seven".