81801232 has 40 divisors (see below), whose sum is σ = 170926560. Its totient is φ = 37797120.

The previous prime is 81801221. The next prime is 81801253. The reversal of 81801232 is 23210818.

It is a junction number, because it is equal to n+sod(n) for n = 81801197 and 81801206.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9183 + ... + 15745.

It is an arithmetic number, because the mean of its divisors is an integer number (4273164).

Almost surely, 2^81801232 is an apocalyptic number.

81801232 is a gapful number since it is divisible by the number (82) 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 81801232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85463280).

81801232 is an abundant number, since it is smaller than the sum of its proper divisors (89125328).

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

81801232 is a wasteful number, since it uses less digits than its factorization.

81801232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6631 (or 6625 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 81801232 is about 9044.4033523500. The cubic root of 81801232 is about 434.0968304547.

The spelling of 81801232 in words is "eighty-one million, eight hundred one thousand, two hundred thirty-two".