81727967 has 2 divisors, whose sum is σ = 81727968. Its totient is φ = 81727966.

The previous prime is 81727957. The next prime is 81727979. The reversal of 81727967 is 76972718.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81727967 - 2¹² = 81723871 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 (81727927) 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, 40863983 + 40863984.

It is an arithmetic number, because the mean of its divisors is an integer number (40863984).

Almost surely, 2^81727967 is an apocalyptic number.

81727967 is a deficient number, since it is larger than the sum of its proper divisors (1).

81727967 is an equidigital number, since it uses as much as digits as its factorization.

81727967 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 296352, while the sum is 47.

The square root of 81727967 is about 9040.3521502207. The cubic root of 81727967 is about 433.9671926187.

The spelling of 81727967 in words is "eighty-one million, seven hundred twenty-seven thousand, nine hundred sixty-seven".