81636337 has 2 divisors, whose sum is σ = 81636338. Its totient is φ = 81636336.

The previous prime is 81636283. The next prime is 81636383. The reversal of 81636337 is 73363618.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61214976 + 20421361 = 7824^2 + 4519^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81636337 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81636296 and 81636305.

It is not a weakly prime, because it can be changed into another prime (81636437) 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, 40818168 + 40818169.

It is an arithmetic number, because the mean of its divisors is an integer number (40818169).

Almost surely, 2^81636337 is an apocalyptic number.

It is an amenable number.

81636337 is a deficient number, since it is larger than the sum of its proper divisors (1).

81636337 is an equidigital number, since it uses as much as digits as its factorization.

81636337 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54432, while the sum is 37.

The square root of 81636337 is about 9035.2828954051. The cubic root of 81636337 is about 433.8049499768.

The spelling of 81636337 in words is "eighty-one million, six hundred thirty-six thousand, three hundred thirty-seven".