81549792 has 36 divisors (see below), whose sum is σ = 231908040. Its totient is φ = 27183168.

The previous prime is 81549791. The next prime is 81549803. The reversal of 81549792 is 29794518.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81549791) 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 5 ways as a sum of consecutive naturals, for example, 141292 + ... + 141867.

It is an arithmetic number, because the mean of its divisors is an integer number (6441890).

Almost surely, 2^81549792 is an apocalyptic number.

It is an amenable number.

81549792 is an abundant number, since it is smaller than the sum of its proper divisors (150358248).

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

81549792 is a wasteful number, since it uses less digits than its factorization.

81549792 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283175 (or 283164 counting only the distinct ones).

The product of its digits is 181440, while the sum is 45.

The square root of 81549792 is about 9030.4923453818. The cubic root of 81549792 is about 433.6515994565.

The spelling of 81549792 in words is "eighty-one million, five hundred forty-nine thousand, seven hundred ninety-two".