81306497 has 2 divisors, whose sum is σ = 81306498. Its totient is φ = 81306496.

The previous prime is 81306487. The next prime is 81306503. The reversal of 81306497 is 79460318.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65869456 + 15437041 = 8116^2 + 3929^2 .

It is a cyclic number.

It is not a de Polignac number, because 81306497 - 2¹⁶ = 81240961 is a prime.

It is a super-2 number, since 2×81306497² = 13221492908822018, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81306497.

It is not a weakly prime, because it can be changed into another prime (81306437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40653248 + 40653249.

It is an arithmetic number, because the mean of its divisors is an integer number (40653249).

Almost surely, 2^81306497 is an apocalyptic number.

It is an amenable number.

81306497 is a deficient number, since it is larger than the sum of its proper divisors (1).

81306497 is an equidigital number, since it uses as much as digits as its factorization.

81306497 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 81306497 is about 9017.0115337622. The cubic root of 81306497 is about 433.2199189714.

The spelling of 81306497 in words is "eighty-one million, three hundred six thousand, four hundred ninety-seven".