81338339 has 2 divisors, whose sum is σ = 81338340. Its totient is φ = 81338338.

The previous prime is 81338329. The next prime is 81338363. The reversal of 81338339 is 93383318.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81338339 is a prime.

It is not a weakly prime, because it can be changed into another prime (81338329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40669169 + 40669170.

It is an arithmetic number, because the mean of its divisors is an integer number (40669170).

Almost surely, 2^81338339 is an apocalyptic number.

81338339 is a deficient number, since it is larger than the sum of its proper divisors (1).

81338339 is an equidigital number, since it uses as much as digits as its factorization.

81338339 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46656, while the sum is 38.

The square root of 81338339 is about 9018.7770235215. Note that the first 3 decimals coincide. The cubic root of 81338339 is about 433.2764654499.

The spelling of 81338339 in words is "eighty-one million, three hundred thirty-eight thousand, three hundred thirty-nine".