81682212 has 48 divisors (see below), whose sum is σ = 208776960. Its totient is φ = 24740352.

The previous prime is 81682201. The next prime is 81682217. The reversal of 81682212 is 21228618.

It is a self number, because there is not a number n which added to its sum of digits gives 81682212.

It is not an unprimeable number, because it can be changed into a prime (81682217) 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, 988 + ... + 12819.

It is an arithmetic number, because the mean of its divisors is an integer number (4349520).

Almost surely, 2^81682212 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 81682212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104388480).

81682212 is an abundant number, since it is smaller than the sum of its proper divisors (127094748).

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

81682212 is a wasteful number, since it uses less digits than its factorization.

81682212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13860 (or 13858 counting only the distinct ones).

The product of its digits is 3072, while the sum is 30.

The square root of 81682212 is about 9037.8211976117. The cubic root of 81682212 is about 433.8861927022.

It can be divided in two parts, 816 and 82212, that added together give a triangular number (83028 = T₄₀₇).

The spelling of 81682212 in words is "eighty-one million, six hundred eighty-two thousand, two hundred twelve".