81105133 has 2 divisors, whose sum is σ = 81105134. Its totient is φ = 81105132.

The previous prime is 81105131. The next prime is 81105139. The reversal of 81105133 is 33150118.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64352484 + 16752649 = 8022^2 + 4093^2 .

It is a cyclic number.

It is not a de Polignac number, because 81105133 - 2¹ = 81105131 is a prime.

Together with 81105131, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81105131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40552566 + 40552567.

It is an arithmetic number, because the mean of its divisors is an integer number (40552567).

Almost surely, 2^81105133 is an apocalyptic number.

It is an amenable number.

81105133 is a deficient number, since it is larger than the sum of its proper divisors (1).

81105133 is an equidigital number, since it uses as much as digits as its factorization.

81105133 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 81105133 is about 9005.8388282269. The cubic root of 81105133 is about 432.8619852528.

The spelling of 81105133 in words is "eighty-one million, one hundred five thousand, one hundred thirty-three".