81028143 has 24 divisors (see below), whose sum is σ = 135070208. Its totient is φ = 45848592.

The previous prime is 81028139. The next prime is 81028147. The reversal of 81028143 is 34182018.

It is an interprime number because it is at equal distance from previous prime (81028139) and next prime (81028147).

It is not a de Polignac number, because 81028143 - 2² = 81028139 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81028147) 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 in 23 ways as a sum of consecutive naturals, for example, 246 + ... + 12732.

Almost surely, 2^81028143 is an apocalyptic number.

81028143 is a deficient number, since it is larger than the sum of its proper divisors (54042065).

81028143 is a wasteful number, since it uses less digits than its factorization.

81028143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12603 (or 12600 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 81028143 is about 9001.5633642162. The cubic root of 81028143 is about 432.7249754499.

The spelling of 81028143 in words is "eighty-one million, twenty-eight thousand, one hundred forty-three".