81560249 has 2 divisors, whose sum is σ = 81560250. Its totient is φ = 81560248.

The previous prime is 81560201. The next prime is 81560257. The reversal of 81560249 is 94206518.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55875625 + 25684624 = 7475^2 + 5068^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81560249 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81560279) 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, 40780124 + 40780125.

It is an arithmetic number, because the mean of its divisors is an integer number (40780125).

Almost surely, 2^81560249 is an apocalyptic number.

It is an amenable number.

81560249 is a deficient number, since it is larger than the sum of its proper divisors (1).

81560249 is an equidigital number, since it uses as much as digits as its factorization.

81560249 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 81560249 is about 9031.0713096509. The cubic root of 81560249 is about 433.6701341491.

The spelling of 81560249 in words is "eighty-one million, five hundred sixty thousand, two hundred forty-nine".