81325760069 has 2 divisors, whose sum is σ = 81325760070. Its totient is φ = 81325760068.

The previous prime is 81325759997. The next prime is 81325760071. The reversal of 81325760069 is 96006752318.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75773572900 + 5552187169 = 275270^2 + 74513^2 .

It is a cyclic number.

It is not a de Polignac number, because 81325760069 - 2⁸ = 81325759813 is a prime.

It is a super-2 number, since 2×81325760069² (a number of 23 digits) contains 22 as substring.

Together with 81325760071, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81325730069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40662880034 + 40662880035.

It is an arithmetic number, because the mean of its divisors is an integer number (40662880035).

Almost surely, 2^81325760069 is an apocalyptic number.

It is an amenable number.

81325760069 is a deficient number, since it is larger than the sum of its proper divisors (1).

81325760069 is an equidigital number, since it uses as much as digits as its factorization.

81325760069 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 544320, while the sum is 47.

The spelling of 81325760069 in words is "eighty-one billion, three hundred twenty-five million, seven hundred sixty thousand, sixty-nine".