81333823 has 2 divisors, whose sum is σ = 81333824. Its totient is φ = 81333822.

The previous prime is 81333799. The next prime is 81333859. The reversal of 81333823 is 32833318.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81333823 - 2⁹ = 81333311 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81333883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40666911 + 40666912.

It is an arithmetic number, because the mean of its divisors is an integer number (40666912).

Almost surely, 2^81333823 is an apocalyptic number.

81333823 is a deficient number, since it is larger than the sum of its proper divisors (1).

81333823 is an equidigital number, since it uses as much as digits as its factorization.

81333823 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 31.

The square root of 81333823 is about 9018.5266535061. The cubic root of 81333823 is about 433.2684466290.

The spelling of 81333823 in words is "eighty-one million, three hundred thirty-three thousand, eight hundred twenty-three".