81143799 has 8 divisors (see below), whose sum is σ = 118027392. Its totient is φ = 49178040.

The previous prime is 81143791. The next prime is 81143801. The reversal of 81143799 is 99734118.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81143799 - 2³ = 81143791 is a prime.

It is a super-2 number, since 2×81143799² = 13168632232304802, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81143799.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81143791) 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 in 7 ways as a sum of consecutive naturals, for example, 1229419 + ... + 1229484.

It is an arithmetic number, because the mean of its divisors is an integer number (14753424).

Almost surely, 2^81143799 is an apocalyptic number.

81143799 is a deficient number, since it is larger than the sum of its proper divisors (36883593).

81143799 is a wasteful number, since it uses less digits than its factorization.

81143799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2458917.

The product of its digits is 54432, while the sum is 42.

The square root of 81143799 is about 9007.9852908406. The cubic root of 81143799 is about 432.9307617567.

The spelling of 81143799 in words is "eighty-one million, one hundred forty-three thousand, seven hundred ninety-nine".