81143659 has 2 divisors, whose sum is σ = 81143660. Its totient is φ = 81143658.

The previous prime is 81143651. The next prime is 81143663. The reversal of 81143659 is 95634118.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81143659 - 2³ = 81143651 is a prime.

It is not a weakly prime, because it can be changed into another prime (81143651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40571829 + 40571830.

It is an arithmetic number, because the mean of its divisors is an integer number (40571830).

Almost surely, 2^81143659 is an apocalyptic number.

81143659 is a deficient number, since it is larger than the sum of its proper divisors (1).

81143659 is an equidigital number, since it uses as much as digits as its factorization.

81143659 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 37.

The square root of 81143659 is about 9007.9775199542. The cubic root of 81143659 is about 432.9305127735.

The spelling of 81143659 in words is "eighty-one million, one hundred forty-three thousand, six hundred fifty-nine".