81142571 has 2 divisors, whose sum is σ = 81142572. Its totient is φ = 81142570.

The previous prime is 81142553. The next prime is 81142603. The reversal of 81142571 is 17524118.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81142571 - 2⁶ = 81142507 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81142511) 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, 40571285 + 40571286.

It is an arithmetic number, because the mean of its divisors is an integer number (40571286).

Almost surely, 2^81142571 is an apocalyptic number.

81142571 is a deficient number, since it is larger than the sum of its proper divisors (1).

81142571 is an equidigital number, since it uses as much as digits as its factorization.

81142571 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2240, while the sum is 29.

The square root of 81142571 is about 9007.9171288373. The cubic root of 81142571 is about 432.9285778081.

Adding to 81142571 its reverse (17524118), we get a palindrome (98666689).

The spelling of 81142571 in words is "eighty-one million, one hundred forty-two thousand, five hundred seventy-one".