81881143 has 2 divisors, whose sum is σ = 81881144. Its totient is φ = 81881142.

The previous prime is 81881117. The next prime is 81881153. The reversal of 81881143 is 34118818.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81881143 - 2¹³ = 81872951 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81881099 and 81881108.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81881153) 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, 40940571 + 40940572.

It is an arithmetic number, because the mean of its divisors is an integer number (40940572).

Almost surely, 2^81881143 is an apocalyptic number.

81881143 is a deficient number, since it is larger than the sum of its proper divisors (1).

81881143 is an equidigital number, since it uses as much as digits as its factorization.

81881143 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6144, while the sum is 34.

The square root of 81881143 is about 9048.8199783176. The cubic root of 81881143 is about 434.2381397449.

The spelling of 81881143 in words is "eighty-one million, eight hundred eighty-one thousand, one hundred forty-three".