81814824 has 96 divisors (see below), whose sum is σ = 272737920. Its totient is φ = 21575808.

The previous prime is 81814801. The next prime is 81814867. The reversal of 81814824 is 42841818.

It is a happy number.

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 polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 309 + ... + 12795.

It is an arithmetic number, because the mean of its divisors is an integer number (2841020).

Almost surely, 2^81814824 is an apocalyptic number.

81814824 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 81814824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136368960).

81814824 is an abundant number, since it is smaller than the sum of its proper divisors (190923096).

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

81814824 is a wasteful number, since it uses less digits than its factorization.

81814824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12519 (or 12512 counting only the distinct ones).

The product of its digits is 16384, while the sum is 36.

The square root of 81814824 is about 9045.1547250448. The cubic root of 81814824 is about 434.1208721356.

The spelling of 81814824 in words is "eighty-one million, eight hundred fourteen thousand, eight hundred twenty-four".