81500143 has 2 divisors, whose sum is σ = 81500144. Its totient is φ = 81500142.

The previous prime is 81500129. The next prime is 81500149. The reversal of 81500143 is 34100518.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81500143 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81500149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40750071 + 40750072.

It is an arithmetic number, because the mean of its divisors is an integer number (40750072).

Almost surely, 2^81500143 is an apocalyptic number.

81500143 is a deficient number, since it is larger than the sum of its proper divisors (1).

81500143 is an equidigital number, since it uses as much as digits as its factorization.

81500143 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 81500143 is about 9027.7429626679. The cubic root of 81500143 is about 433.5635765911.

The spelling of 81500143 in words is "eighty-one million, five hundred thousand, one hundred forty-three".