81364123 has 2 divisors, whose sum is σ = 81364124. Its totient is φ = 81364122.

The previous prime is 81364117. The next prime is 81364139. The reversal of 81364123 is 32146318.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81364123 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81364091 and 81364100.

It is not a weakly prime, because it can be changed into another prime (81364223) 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, 40682061 + 40682062.

It is an arithmetic number, because the mean of its divisors is an integer number (40682062).

Almost surely, 2^81364123 is an apocalyptic number.

81364123 is a deficient number, since it is larger than the sum of its proper divisors (1).

81364123 is an equidigital number, since it uses as much as digits as its factorization.

81364123 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3456, while the sum is 28.

The square root of 81364123 is about 9020.2063723620. The cubic root of 81364123 is about 433.3222430429.

The spelling of 81364123 in words is "eighty-one million, three hundred sixty-four thousand, one hundred twenty-three".