81929927 has 2 divisors, whose sum is σ = 81929928. Its totient is φ = 81929926.

The previous prime is 81929909. The next prime is 81929963. The reversal of 81929927 is 72992918.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81929927 - 2²⁰ = 80881351 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81929027) 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, 40964963 + 40964964.

It is an arithmetic number, because the mean of its divisors is an integer number (40964964).

Almost surely, 2^81929927 is an apocalyptic number.

81929927 is a deficient number, since it is larger than the sum of its proper divisors (1).

81929927 is an equidigital number, since it uses as much as digits as its factorization.

81929927 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 163296, while the sum is 47.

The square root of 81929927 is about 9051.5151770298. The cubic root of 81929927 is about 434.3243609308.

The spelling of 81929927 in words is "eighty-one million, nine hundred twenty-nine thousand, nine hundred twenty-seven".