80136220781 has 2 divisors, whose sum is σ = 80136220782. Its totient is φ = 80136220780.

The previous prime is 80136220741. The next prime is 80136220793. The reversal of 80136220781 is 18702263108.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79936252900 + 199967881 = 282730^2 + 14141^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-80136220781 is a prime.

It is a super-2 number, since 2×80136220781² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (80136220721) 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, 40068110390 + 40068110391.

It is an arithmetic number, because the mean of its divisors is an integer number (40068110391).

Almost surely, 2^80136220781 is an apocalyptic number.

It is an amenable number.

80136220781 is a deficient number, since it is larger than the sum of its proper divisors (1).

80136220781 is an equidigital number, since it uses as much as digits as its factorization.

80136220781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32256, while the sum is 38.

Adding to 80136220781 its reverse (18702263108), we get a palindrome (98838483889).

The spelling of 80136220781 in words is "eighty billion, one hundred thirty-six million, two hundred twenty thousand, seven hundred eighty-one".