81968408 has 16 divisors (see below), whose sum is σ = 153846000. Its totient is φ = 40942816.

The previous prime is 81968401. The next prime is 81968417. The reversal of 81968408 is 80486918.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81968401) 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 3 ways as a sum of consecutive naturals, for example, 4253 + ... + 13491.

It is an arithmetic number, because the mean of its divisors is an integer number (9615375).

Almost surely, 2^81968408 is an apocalyptic number.

It is an amenable number.

81968408 is a deficient number, since it is larger than the sum of its proper divisors (71877592).

81968408 is a wasteful number, since it uses less digits than its factorization.

81968408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10354 (or 10350 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 44.

The square root of 81968408 is about 9053.6405937059. The cubic root of 81968408 is about 434.3923483781.

The spelling of 81968408 in words is "eighty-one million, nine hundred sixty-eight thousand, four hundred eight".