81339733 has 2 divisors, whose sum is σ = 81339734. Its totient is φ = 81339732.

The previous prime is 81339721. The next prime is 81339761. The reversal of 81339733 is 33793318.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46553329 + 34786404 = 6823^2 + 5898^2 .

It is a cyclic number.

It is not a de Polignac number, because 81339733 - 2⁹ = 81339221 is a prime.

It is a super-2 number, since 2×81339733² = 13232304329022578, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81339692 and 81339701.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81339793) 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, 40669866 + 40669867.

It is an arithmetic number, because the mean of its divisors is an integer number (40669867).

Almost surely, 2^81339733 is an apocalyptic number.

It is an amenable number.

81339733 is a deficient number, since it is larger than the sum of its proper divisors (1).

81339733 is an equidigital number, since it uses as much as digits as its factorization.

81339733 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40824, while the sum is 37.

The square root of 81339733 is about 9018.8543063961. The cubic root of 81339733 is about 433.2789406416.

The spelling of 81339733 in words is "eighty-one million, three hundred thirty-nine thousand, seven hundred thirty-three".