81773568 has 132 divisors (see below), whose sum is σ = 249078960. Its totient is φ = 25767936.

The previous prime is 81773551. The next prime is 81773569. The reversal of 81773568 is 86537718.

81773568 is a `hidden beast` number, since 8 + 17 + 73 + 568 = 666.

It is not an unprimeable number, because it can be changed into a prime (81773569) 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 11 ways as a sum of consecutive naturals, for example, 174871 + ... + 175337.

Almost surely, 2^81773568 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 81773568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124539480).

81773568 is an abundant number, since it is smaller than the sum of its proper divisors (167305392).

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

81773568 is a wasteful number, since it uses less digits than its factorization.

81773568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 512 (or 491 counting only the distinct ones).

The product of its digits is 282240, while the sum is 45.

The square root of 81773568 is about 9042.8738794700. The cubic root of 81773568 is about 434.0478898360.

The spelling of 81773568 in words is "eighty-one million, seven hundred seventy-three thousand, five hundred sixty-eight".