81396233 has 2 divisors, whose sum is σ = 81396234. Its totient is φ = 81396232.

The previous prime is 81396229. The next prime is 81396239. The reversal of 81396233 is 33269318.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 62141689 + 19254544 = 7883^2 + 4388^2 .

It is a cyclic number.

It is not a de Polignac number, because 81396233 - 2² = 81396229 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 81396193 and 81396202.

It is not a weakly prime, because it can be changed into another prime (81396239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40698116 + 40698117.

It is an arithmetic number, because the mean of its divisors is an integer number (40698117).

Almost surely, 2^81396233 is an apocalyptic number.

It is an amenable number.

81396233 is a deficient number, since it is larger than the sum of its proper divisors (1).

81396233 is an equidigital number, since it uses as much as digits as its factorization.

81396233 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23328, while the sum is 35.

The square root of 81396233 is about 9021.9860895481. The cubic root of 81396233 is about 433.3792384636.

The spelling of 81396233 in words is "eighty-one million, three hundred ninety-six thousand, two hundred thirty-three".