81161472 has 144 divisors (see below), whose sum is σ = 255352832. Its totient is φ = 22394880.

The previous prime is 81161471. The next prime is 81161477. The reversal of 81161472 is 27416118.

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81161471) 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 15 ways as a sum of consecutive naturals, for example, 166413 + ... + 166899.

Almost surely, 2^81161472 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 81161472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127676416).

81161472 is an abundant number, since it is smaller than the sum of its proper divisors (174191360).

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

81161472 is a wasteful number, since it uses less digits than its factorization.

81161472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 544 (or 530 counting only the distinct ones).

The product of its digits is 2688, while the sum is 30.

The square root of 81161472 is about 9008.9662004028. The cubic root of 81161472 is about 432.9621900361.

The spelling of 81161472 in words is "eighty-one million, one hundred sixty-one thousand, four hundred seventy-two".