81682272 has 144 divisors (see below), whose sum is σ = 274240512. Its totient is φ = 22567680.

The previous prime is 81682267. The next prime is 81682283. The reversal of 81682272 is 27228618.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (144).

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, 61843 + ... + 63149.

It is an arithmetic number, because the mean of its divisors is an integer number (1904448).

Almost surely, 2^81682272 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 81682272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (137120256).

81682272 is an abundant number, since it is smaller than the sum of its proper divisors (192558240).

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

81682272 is a wasteful number, since it uses less digits than its factorization.

81682272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1361 (or 1350 counting only the distinct ones).

The product of its digits is 21504, while the sum is 36.

The square root of 81682272 is about 9037.8245169952. The cubic root of 81682272 is about 433.8862989398.

It can be divided in two parts, 8168 and 2272, that added together give a triangular number (10440 = T₁₄₄).

The spelling of 81682272 in words is "eighty-one million, six hundred eighty-two thousand, two hundred seventy-two".