81396143 has 4 divisors (see below), whose sum is σ = 82730568. Its totient is φ = 80061720.

The previous prime is 81396109. The next prime is 81396199. The reversal of 81396143 is 34169318.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81396143 - 2⁶ = 81396079 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81396443) 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 3 ways as a sum of consecutive naturals, for example, 667121 + ... + 667242.

It is an arithmetic number, because the mean of its divisors is an integer number (20682642).

Almost surely, 2^81396143 is an apocalyptic number.

81396143 is a deficient number, since it is larger than the sum of its proper divisors (1334425).

81396143 is a wasteful number, since it uses less digits than its factorization.

81396143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1334424.

The product of its digits is 15552, while the sum is 35.

The square root of 81396143 is about 9021.9811017315. The cubic root of 81396143 is about 433.3790787341.

The spelling of 81396143 in words is "eighty-one million, three hundred ninety-six thousand, one hundred forty-three".