81633168 has 60 divisors (see below), whose sum is σ = 235842048. Its totient is φ = 26331840.

The previous prime is 81633151. The next prime is 81633193. The reversal of 81633168 is 86133618.

81633168 is a `hidden beast` number, since 8 + 1 + 633 + 16 + 8 = 666.

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 an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4680 + ... + 13607.

Almost surely, 2^81633168 is an apocalyptic number.

It is an amenable number.

81633168 is an abundant number, since it is smaller than the sum of its proper divisors (154208880).

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

81633168 is a wasteful number, since it uses less digits than its factorization.

81633168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18332 (or 18323 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 81633168 is about 9035.1075256468. The cubic root of 81633168 is about 433.7993366852.

The spelling of 81633168 in words is "eighty-one million, six hundred thirty-three thousand, one hundred sixty-eight".