81272371 has 2 divisors, whose sum is σ = 81272372. Its totient is φ = 81272370.

The previous prime is 81272357. The next prime is 81272419. The reversal of 81272371 is 17327218.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81272371 - 2⁵ = 81272339 is a prime.

It is not a weakly prime, because it can be changed into another prime (81272311) 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, 40636185 + 40636186.

It is an arithmetic number, because the mean of its divisors is an integer number (40636186).

Almost surely, 2^81272371 is an apocalyptic number.

81272371 is a deficient number, since it is larger than the sum of its proper divisors (1).

81272371 is an equidigital number, since it uses as much as digits as its factorization.

81272371 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4704, while the sum is 31.

The square root of 81272371 is about 9015.1190230634. The cubic root of 81272371 is about 433.1593000689.

Adding to 81272371 its reverse (17327218), we get a palindrome (98599589).

The spelling of 81272371 in words is "eighty-one million, two hundred seventy-two thousand, three hundred seventy-one".