81143712 has 72 divisors (see below), whose sum is σ = 248514084. Its totient is φ = 24966144.

The previous prime is 81143707. The next prime is 81143719. The reversal of 81143712 is 21734118.

It can be written as a sum of positive squares in 2 ways, for example, as 79495056 + 1648656 = 8916^2 + 1284^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is not an unprimeable number, because it can be changed into a prime (81143719) 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, 7093 + ... + 14580.

Almost surely, 2^81143712 is an apocalyptic number.

It is an amenable number.

81143712 is an abundant number, since it is smaller than the sum of its proper divisors (167370372).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81143712 is a wasteful number, since it uses less digits than its factorization.

81143712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21702 (or 21691 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 81143712 is about 9007.9804617905. The cubic root of 81143712 is about 432.9306070314.

The spelling of 81143712 in words is "eighty-one million, one hundred forty-three thousand, seven hundred twelve".