81143447 has 12 divisors (see below), whose sum is σ = 101933328. Its totient is φ = 63228000.

The previous prime is 81143437. The next prime is 81143449. The reversal of 81143447 is 74434118.

It is not a de Polignac number, because 81143447 - 2¹⁰ = 81142423 is a prime.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81143449) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 47054 + ... + 48747.

It is an arithmetic number, because the mean of its divisors is an integer number (8494444).

Almost surely, 2^81143447 is an apocalyptic number.

81143447 is a deficient number, since it is larger than the sum of its proper divisors (20789881).

81143447 is a wasteful number, since it uses less digits than its factorization.

81143447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95830 (or 95819 counting only the distinct ones).

The product of its digits is 10752, while the sum is 32.

The square root of 81143447 is about 9007.9657525992. The cubic root of 81143447 is about 432.9301357411.

The spelling of 81143447 in words is "eighty-one million, one hundred forty-three thousand, four hundred forty-seven".