81428844 has 96 divisors (see below), whose sum is σ = 232243200. Its totient is φ = 21676032.

The previous prime is 81428843. The next prime is 81428849. The reversal of 81428844 is 44882418.

It is not an unprimeable number, because it can be changed into a prime (81428843) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 181132 + ... + 181580.

It is an arithmetic number, because the mean of its divisors is an integer number (2419200).

Almost surely, 2^81428844 is an apocalyptic number.

81428844 is a gapful number since it is divisible by the number (84) 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 81428844, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116121600).

81428844 is an abundant number, since it is smaller than the sum of its proper divisors (150814356).

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

81428844 is a wasteful number, since it uses less digits than its factorization.

81428844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 607 (or 605 counting only the distinct ones).

The product of its digits is 65536, while the sum is 39.

The square root of 81428844 is about 9023.7932157159. The cubic root of 81428844 is about 433.4371078220.

The spelling of 81428844 in words is "eighty-one million, four hundred twenty-eight thousand, eight hundred forty-four".