81647827 has 2 divisors, whose sum is σ = 81647828. Its totient is φ = 81647826.

The previous prime is 81647777. The next prime is 81647837. The reversal of 81647827 is 72874618.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81647827 - 2¹¹ = 81645779 is a prime.

It is not a weakly prime, because it can be changed into another prime (81647837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40823913 + 40823914.

It is an arithmetic number, because the mean of its divisors is an integer number (40823914).

Almost surely, 2^81647827 is an apocalyptic number.

81647827 is a deficient number, since it is larger than the sum of its proper divisors (1).

81647827 is an equidigital number, since it uses as much as digits as its factorization.

81647827 is an evil number, because the sum of its binary digits is even.

The product of its digits is 150528, while the sum is 43.

The square root of 81647827 is about 9035.9187136671. The cubic root of 81647827 is about 433.8253011473.

The spelling of 81647827 in words is "eighty-one million, six hundred forty-seven thousand, eight hundred twenty-seven".