81127872 has 224 divisors, whose sum is σ = 287731200. Its totient is φ = 21897216.

The previous prime is 81127867. The next prime is 81127901. The reversal of 81127872 is 27872118.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 229648 + ... + 230000.

Almost surely, 2^81127872 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81127872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143865600).

81127872 is an abundant number, since it is smaller than the sum of its proper divisors (206603328).

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

81127872 is a wasteful number, since it uses less digits than its factorization.

81127872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400 (or 384 counting only the distinct ones).

The product of its digits is 12544, while the sum is 36.

The square root of 81127872 is about 9007.1011984989. The cubic root of 81127872 is about 432.9024345174.

The spelling of 81127872 in words is "eighty-one million, one hundred twenty-seven thousand, eight hundred seventy-two".