81026333281 has 2 divisors, whose sum is σ = 81026333282. Its totient is φ = 81026333280.

The previous prime is 81026333197. The next prime is 81026333287. The reversal of 81026333281 is 18233362018.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42288220881 + 38738112400 = 205641^2 + 196820^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81026333281 is a prime.

It is a super-2 number, since 2×81026333281² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81026333281.

It is not a weakly prime, because it can be changed into another prime (81026333287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40513166640 + 40513166641.

It is an arithmetic number, because the mean of its divisors is an integer number (40513166641).

Almost surely, 2^81026333281 is an apocalyptic number.

It is an amenable number.

81026333281 is a deficient number, since it is larger than the sum of its proper divisors (1).

81026333281 is an equidigital number, since it uses as much as digits as its factorization.

81026333281 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 37.

Adding to 81026333281 its reverse (18233362018), we get a palindrome (99259695299).

The spelling of 81026333281 in words is "eighty-one billion, twenty-six million, three hundred thirty-three thousand, two hundred eighty-one".