81691627763 has 2 divisors, whose sum is σ = 81691627764. Its totient is φ = 81691627762.

The previous prime is 81691627741. The next prime is 81691627777. The reversal of 81691627763 is 36772619618.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81691627763 - 2³⁴ = 64511758579 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81691627699 and 81691627708.

It is not a weakly prime, because it can be changed into another prime (81691627163) 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, 40845813881 + 40845813882.

It is an arithmetic number, because the mean of its divisors is an integer number (40845813882).

Almost surely, 2^81691627763 is an apocalyptic number.

81691627763 is a deficient number, since it is larger than the sum of its proper divisors (1).

81691627763 is an equidigital number, since it uses as much as digits as its factorization.

81691627763 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4572288, while the sum is 56.

The spelling of 81691627763 in words is "eighty-one billion, six hundred ninety-one million, six hundred twenty-seven thousand, seven hundred sixty-three".