81612143 has 2 divisors, whose sum is σ = 81612144. Its totient is φ = 81612142.

The previous prime is 81612137. The next prime is 81612161. The reversal of 81612143 is 34121618.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81612143 - 2⁶ = 81612079 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81615143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40806071 + 40806072.

It is an arithmetic number, because the mean of its divisors is an integer number (40806072).

Almost surely, 2^81612143 is an apocalyptic number.

81612143 is a deficient number, since it is larger than the sum of its proper divisors (1).

81612143 is an equidigital number, since it uses as much as digits as its factorization.

81612143 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1152, while the sum is 26.

The square root of 81612143 is about 9033.9439338530. The cubic root of 81612143 is about 433.7620911456.

The spelling of 81612143 in words is "eighty-one million, six hundred twelve thousand, one hundred forty-three".