81127680 has 144 divisors (see below), whose sum is σ = 266570304. Its totient is φ = 21012480.

The previous prime is 81127679. The next prime is 81127691. The reversal of 81127680 is 8672118.

It is a happy number.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 141795 + ... + 142365.

Almost surely, 2^81127680 is an apocalyptic number.

81127680 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81127680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133285152).

81127680 is an abundant number, since it is smaller than the sum of its proper divisors (185442624).

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

81127680 is a wasteful number, since it uses less digits than its factorization.

81127680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 632 (or 618 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 33.

The square root of 81127680 is about 9007.0905402355. The cubic root of 81127680 is about 432.9020930099.

Adding to 81127680 its reverse (8672118), we get a palindrome (89799798).

The spelling of 81127680 in words is "eighty-one million, one hundred twenty-seven thousand, six hundred eighty".