81968184 has 48 divisors (see below), whose sum is σ = 227419920. Its totient is φ = 26655360.

The previous prime is 81968179. The next prime is 81968189. The reversal of 81968184 is 48186918.

It is an interprime number because it is at equal distance from previous prime (81968179) and next prime (81968189).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81968189) 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 11 ways as a sum of consecutive naturals, for example, 10932 + ... + 16835.

It is an arithmetic number, because the mean of its divisors is an integer number (4737915).

Almost surely, 2^81968184 is an apocalyptic number.

It is an amenable number.

81968184 is an abundant number, since it is smaller than the sum of its proper divisors (145451736).

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

81968184 is a wasteful number, since it uses less digits than its factorization.

81968184 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27820 (or 27813 counting only the distinct ones).

The product of its digits is 110592, while the sum is 45.

The square root of 81968184 is about 9053.6282229833. The cubic root of 81968184 is about 434.3919526810.

The spelling of 81968184 in words is "eighty-one million, nine hundred sixty-eight thousand, one hundred eighty-four".