81549168 has 40 divisors (see below), whose sum is σ = 219831168. Its totient is φ = 26000832.

The previous prime is 81549157. The next prime is 81549173. The reversal of 81549168 is 86194518.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35830 + ... + 38037.

Almost surely, 2^81549168 is an apocalyptic number.

It is an amenable number.

81549168 is an abundant number, since it is smaller than the sum of its proper divisors (138282000).

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

81549168 is a wasteful number, since it uses less digits than its factorization.

81549168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73901 (or 73895 counting only the distinct ones).

The product of its digits is 69120, while the sum is 42.

The square root of 81549168 is about 9030.4577957045. The cubic root of 81549168 is about 433.6504933867.

The spelling of 81549168 in words is "eighty-one million, five hundred forty-nine thousand, one hundred sixty-eight".