81459575969 has 2 divisors, whose sum is σ = 81459575970. Its totient is φ = 81459575968.

The previous prime is 81459575947. The next prime is 81459575987. The reversal of 81459575969 is 96957595418.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47164980625 + 34294595344 = 217175^2 + 185188^2 .

It is a cyclic number.

It is not a de Polignac number, because 81459575969 - 2²⁴ = 81442798753 is a prime.

It is a super-2 number, since 2×81459575969² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81459575899 and 81459575908.

It is not a weakly prime, because it can be changed into another prime (81459575929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40729787984 + 40729787985.

It is an arithmetic number, because the mean of its divisors is an integer number (40729787985).

Almost surely, 2^81459575969 is an apocalyptic number.

It is an amenable number.

81459575969 is a deficient number, since it is larger than the sum of its proper divisors (1).

81459575969 is an equidigital number, since it uses as much as digits as its factorization.

81459575969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 122472000, while the sum is 68.

The spelling of 81459575969 in words is "eighty-one billion, four hundred fifty-nine million, five hundred seventy-five thousand, nine hundred sixty-nine".