81412217 has 2 divisors, whose sum is σ = 81412218. Its totient is φ = 81412216.

The previous prime is 81412211. The next prime is 81412229. The reversal of 81412217 is 71221418.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66520336 + 14891881 = 8156^2 + 3859^2 .

It is a cyclic number.

It is not a de Polignac number, because 81412217 - 2¹⁰ = 81411193 is a prime.

It is not a weakly prime, because it can be changed into another prime (81412211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40706108 + 40706109.

It is an arithmetic number, because the mean of its divisors is an integer number (40706109).

Almost surely, 2^81412217 is an apocalyptic number.

It is an amenable number.

81412217 is a deficient number, since it is larger than the sum of its proper divisors (1).

81412217 is an equidigital number, since it uses as much as digits as its factorization.

81412217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 896, while the sum is 26.

The square root of 81412217 is about 9022.8718820562. The cubic root of 81412217 is about 433.4076045608.

It can be divided in two parts, 814 and 12217, that added together give a palindrome (13031).

The spelling of 81412217 in words is "eighty-one million, four hundred twelve thousand, two hundred seventeen".