81617382 has 112 divisors (see below), whose sum is σ = 229162752. Its totient is φ = 21170160.

The previous prime is 81617381. The next prime is 81617383. The reversal of 81617382 is 28371618.

81617382 is a `hidden beast` number, since 8 + 1 + 617 + 38 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (81617381) and next prime (81617383).

It is a super-2 number, since 2×81617382² = 13322794089067848, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81617381) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 111903 + ... + 112629.

It is an arithmetic number, because the mean of its divisors is an integer number (2046096).

Almost surely, 2^81617382 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81617382, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114581376).

81617382 is an abundant number, since it is smaller than the sum of its proper divisors (147545370).

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

81617382 is a wasteful number, since it uses less digits than its factorization.

81617382 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 765 (or 750 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 81617382 is about 9034.2338911498. The cubic root of 81617382 is about 433.7713725707.

The spelling of 81617382 in words is "eighty-one million, six hundred seventeen thousand, three hundred eighty-two".