81132091 has 2 divisors, whose sum is σ = 81132092. Its totient is φ = 81132090.

The previous prime is 81132067. The next prime is 81132113. The reversal of 81132091 is 19023118.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81132091 - 2⁵ = 81132059 is a prime.

It is not a weakly prime, because it can be changed into another prime (81132031) 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, 40566045 + 40566046.

It is an arithmetic number, because the mean of its divisors is an integer number (40566046).

Almost surely, 2^81132091 is an apocalyptic number.

81132091 is a deficient number, since it is larger than the sum of its proper divisors (1).

81132091 is an equidigital number, since it uses as much as digits as its factorization.

81132091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 81132091 is about 9007.3353995507. The cubic root of 81132091 is about 432.9099386533.

The spelling of 81132091 in words is "eighty-one million, one hundred thirty-two thousand, ninety-one".