81648144 has 60 divisors (see below), whose sum is σ = 241949916. Its totient is φ = 25614336.

The previous prime is 81648139. The next prime is 81648157. The reversal of 81648144 is 44184618.

81648144 is a `hidden beast` number, since 8 + 1 + 648 + 1 + 4 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 33872400 + 47775744 = 5820^2 + 6912^2 .

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 junction number, because it is equal to n+sod(n) for n = 81648099 and 81648108.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 14229 + ... + 19124.

Almost surely, 2^81648144 is an apocalyptic number.

It is an amenable number.

81648144 is an abundant number, since it is smaller than the sum of its proper divisors (160301772).

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

81648144 is a wasteful number, since it uses less digits than its factorization.

81648144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33384 (or 33375 counting only the distinct ones).

The product of its digits is 24576, while the sum is 36.

The square root of 81648144 is about 9035.9362547552. The cubic root of 81648144 is about 433.8258625929.

The spelling of 81648144 in words is "eighty-one million, six hundred forty-eight thousand, one hundred forty-four".