81431023 has 2 divisors, whose sum is σ = 81431024. Its totient is φ = 81431022.

The previous prime is 81431011. The next prime is 81431027. The reversal of 81431023 is 32013418.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81431023 - 2²¹ = 79333871 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81430985 and 81431003.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81431027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40715511 + 40715512.

It is an arithmetic number, because the mean of its divisors is an integer number (40715512).

Almost surely, 2^81431023 is an apocalyptic number.

81431023 is a deficient number, since it is larger than the sum of its proper divisors (1).

81431023 is an equidigital number, since it uses as much as digits as its factorization.

81431023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 81431023 is about 9023.9139512741. The cubic root of 81431023 is about 433.4409739829.

The spelling of 81431023 in words is "eighty-one million, four hundred thirty-one thousand, twenty-three".