81208471 has 2 divisors, whose sum is σ = 81208472. Its totient is φ = 81208470.

The previous prime is 81208459. The next prime is 81208481. The reversal of 81208471 is 17480218.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81208471 is a prime.

It is a super-3 number, since 3×81208471³ (a number of 25 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81208411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40604235 + 40604236.

It is an arithmetic number, because the mean of its divisors is an integer number (40604236).

Almost surely, 2^81208471 is an apocalyptic number.

81208471 is a deficient number, since it is larger than the sum of its proper divisors (1).

81208471 is an equidigital number, since it uses as much as digits as its factorization.

81208471 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3584, while the sum is 31.

The square root of 81208471 is about 9011.5742797804. The cubic root of 81208471 is about 433.0457471840.

Adding to 81208471 its reverse (17480218), we get a palindrome (98688689).

The spelling of 81208471 in words is "eighty-one million, two hundred eight thousand, four hundred seventy-one".