81906067 has 2 divisors, whose sum is σ = 81906068. Its totient is φ = 81906066.

The previous prime is 81906053. The next prime is 81906107. The reversal of 81906067 is 76060918.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81906067 - 2¹⁹ = 81381779 is a prime.

It is a super-2 number, since 2×81906067² = 13417207622816978, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81906037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40953033 + 40953034.

It is an arithmetic number, because the mean of its divisors is an integer number (40953034).

Almost surely, 2^81906067 is an apocalyptic number.

81906067 is a deficient number, since it is larger than the sum of its proper divisors (1).

81906067 is an equidigital number, since it uses as much as digits as its factorization.

81906067 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 37.

The square root of 81906067 is about 9050.1970696775. The cubic root of 81906067 is about 434.2821948759.

The spelling of 81906067 in words is "eighty-one million, nine hundred six thousand, sixty-seven".