81132216 has 64 divisors (see below), whose sum is σ = 222566400. Its totient is φ = 24441600.

The previous prime is 81132203. The next prime is 81132217. The reversal of 81132216 is 61223118.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81132217) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49620 + ... + 51228.

It is an arithmetic number, because the mean of its divisors is an integer number (3477600).

Almost surely, 2^81132216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81132216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111283200).

81132216 is an abundant number, since it is smaller than the sum of its proper divisors (141434184).

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

81132216 is a wasteful number, since it uses less digits than its factorization.

81132216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1820 (or 1816 counting only the distinct ones).

The product of its digits is 576, while the sum is 24.

The square root of 81132216 is about 9007.3423383371. The cubic root of 81132216 is about 432.9101609809.

The spelling of 81132216 in words is "eighty-one million, one hundred thirty-two thousand, two hundred sixteen".