81338832 has 60 divisors (see below), whose sum is σ = 229806720. Its totient is φ = 26854464.

The previous prime is 81338827. The next prime is 81338837. The reversal of 81338832 is 23883318.

It is an interprime number because it is at equal distance from previous prime (81338827) and next prime (81338837).

It is a super-2 number, since 2×81338832² = 13232011182248448, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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 not an unprimeable number, because it can be changed into a prime (81338837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12769 + ... + 18047.

It is an arithmetic number, because the mean of its divisors is an integer number (3830112).

Almost surely, 2^81338832 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 81338832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114903360).

81338832 is an abundant number, since it is smaller than the sum of its proper divisors (148467888).

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

81338832 is a wasteful number, since it uses less digits than its factorization.

81338832 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5400 (or 5391 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 81338832 is about 9018.8043553456. The cubic root of 81338832 is about 433.2773408258.

The spelling of 81338832 in words is "eighty-one million, three hundred thirty-eight thousand, eight hundred thirty-two".