81071426321 has 2 divisors, whose sum is σ = 81071426322. Its totient is φ = 81071426320.

The previous prime is 81071426297. The next prime is 81071426341. The reversal of 81071426321 is 12362417018.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61313188225 + 19758238096 = 247615^2 + 140564^2 .

It is a cyclic number.

It is not a de Polignac number, because 81071426321 - 2¹⁰ = 81071425297 is a prime.

It is not a weakly prime, because it can be changed into another prime (81071426341) 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, 40535713160 + 40535713161.

It is an arithmetic number, because the mean of its divisors is an integer number (40535713161).

Almost surely, 2^81071426321 is an apocalyptic number.

It is an amenable number.

81071426321 is a deficient number, since it is larger than the sum of its proper divisors (1).

81071426321 is an equidigital number, since it uses as much as digits as its factorization.

81071426321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16128, while the sum is 35.

The spelling of 81071426321 in words is "eighty-one billion, seventy-one million, four hundred twenty-six thousand, three hundred twenty-one".