81178132 has 48 divisors (see below), whose sum is σ = 170456832. Its totient is φ = 33073920.

The previous prime is 81178103. The next prime is 81178133. The reversal of 81178132 is 23187118.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 81178094 and 81178103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81178133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 149782 + ... + 150322.

It is an arithmetic number, because the mean of its divisors is an integer number (3551184).

Almost surely, 2^81178132 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 81178132, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85228416).

81178132 is an abundant number, since it is smaller than the sum of its proper divisors (89278700).

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

81178132 is a wasteful number, since it uses less digits than its factorization.

81178132 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 808 (or 806 counting only the distinct ones).

The product of its digits is 2688, while the sum is 31.

The square root of 81178132 is about 9009.8907873514. The cubic root of 81178132 is about 432.9918126982.

The spelling of 81178132 in words is "eighty-one million, one hundred seventy-eight thousand, one hundred thirty-two".