81442080 has 144 divisors (see below), whose sum is σ = 290122560. Its totient is φ = 20765184.

The previous prime is 81442061. The next prime is 81442147. The reversal of 81442080 is 8024418.

It is a tau number, because it is divible by the number of its divisors (144).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 31891 + ... + 34349.

It is an arithmetic number, because the mean of its divisors is an integer number (2014740).

Almost surely, 2^81442080 is an apocalyptic number.

81442080 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 81442080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145061280).

81442080 is an abundant number, since it is smaller than the sum of its proper divisors (208680480).

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

81442080 is a wasteful number, since it uses less digits than its factorization.

81442080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2503 (or 2492 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 27.

The square root of 81442080 is about 9024.5265803808. The cubic root of 81442080 is about 433.4605911582.

Adding to 81442080 its reverse (8024418), we get a palindrome (89466498).

The spelling of 81442080 in words is "eighty-one million, four hundred forty-two thousand, eighty".