81475033481 has 2 divisors, whose sum is σ = 81475033482. Its totient is φ = 81475033480.

The previous prime is 81475033433. The next prime is 81475033513. The reversal of 81475033481 is 18433057418.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58216038400 + 23258995081 = 241280^2 + 152509^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81475033481 is a prime.

It is a super-2 number, since 2×81475033481² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81475033421) 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, 40737516740 + 40737516741.

It is an arithmetic number, because the mean of its divisors is an integer number (40737516741).

Almost surely, 2^81475033481 is an apocalyptic number.

It is an amenable number.

81475033481 is a deficient number, since it is larger than the sum of its proper divisors (1).

81475033481 is an equidigital number, since it uses as much as digits as its factorization.

81475033481 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 322560, while the sum is 44.

The spelling of 81475033481 in words is "eighty-one billion, four hundred seventy-five million, thirty-three thousand, four hundred eighty-one".