81384928 has 12 divisors (see below), whose sum is σ = 160226640. Its totient is φ = 40692448.

The previous prime is 81384913. The next prime is 81384937. The reversal of 81384928 is 82948318.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1271608 + ... + 1271671.

It is an arithmetic number, because the mean of its divisors is an integer number (13352220).

Almost surely, 2^81384928 is an apocalyptic number.

It is an amenable number.

81384928 is a deficient number, since it is larger than the sum of its proper divisors (78841712).

81384928 is a wasteful number, since it uses less digits than its factorization.

81384928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2543289 (or 2543281 counting only the distinct ones).

The product of its digits is 110592, while the sum is 43.

The square root of 81384928 is about 9021.3595427740. The cubic root of 81384928 is about 433.3591737385.

The spelling of 81384928 in words is "eighty-one million, three hundred eighty-four thousand, nine hundred twenty-eight".