81117097 has 2 divisors, whose sum is σ = 81117098. Its totient is φ = 81117096.

The previous prime is 81117079. The next prime is 81117119. The reversal of 81117097 is 79071118.

Together with previous prime (81117079) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40908816 + 40208281 = 6396^2 + 6341^2 .

It is a cyclic number.

It is not a de Polignac number, because 81117097 - 2²³ = 72728489 is a prime.

It is not a weakly prime, because it can be changed into another prime (81117397) 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, 40558548 + 40558549.

It is an arithmetic number, because the mean of its divisors is an integer number (40558549).

Almost surely, 2^81117097 is an apocalyptic number.

It is an amenable number.

81117097 is a deficient number, since it is larger than the sum of its proper divisors (1).

81117097 is an equidigital number, since it uses as much as digits as its factorization.

81117097 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3528, while the sum is 34.

The square root of 81117097 is about 9006.5030394710. The cubic root of 81117097 is about 432.8832683536.

The spelling of 81117097 in words is "eighty-one million, one hundred seventeen thousand, ninety-seven".