81153931597 has 2 divisors, whose sum is σ = 81153931598. Its totient is φ = 81153931596.

The previous prime is 81153931567. The next prime is 81153931601. The reversal of 81153931597 is 79513935118.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78414560676 + 2739370921 = 280026^2 + 52339^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81153931597 is a prime.

It is a super-2 number, since 2×81153931597² (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 (81153931567) 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, 40576965798 + 40576965799.

It is an arithmetic number, because the mean of its divisors is an integer number (40576965799).

Almost surely, 2^81153931597 is an apocalyptic number.

It is an amenable number.

81153931597 is a deficient number, since it is larger than the sum of its proper divisors (1).

81153931597 is an equidigital number, since it uses as much as digits as its factorization.

81153931597 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1020600, while the sum is 52.

The spelling of 81153931597 in words is "eighty-one billion, one hundred fifty-three million, nine hundred thirty-one thousand, five hundred ninety-seven".