81628384 has 12 divisors (see below), whose sum is σ = 160705944. Its totient is φ = 40814176.

The previous prime is 81628369. The next prime is 81628399. The reversal of 81628384 is 48382618.

It is an interprime number because it is at equal distance from previous prime (81628369) and next prime (81628399).

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 1275412 + ... + 1275475.

It is an arithmetic number, because the mean of its divisors is an integer number (13392162).

Almost surely, 2^81628384 is an apocalyptic number.

It is an amenable number.

81628384 is a deficient number, since it is larger than the sum of its proper divisors (79077560).

81628384 is a wasteful number, since it uses less digits than its factorization.

81628384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2550897 (or 2550889 counting only the distinct ones).

The product of its digits is 73728, while the sum is 40.

The square root of 81628384 is about 9034.8427767173. The cubic root of 81628384 is about 433.7908624477.

The spelling of 81628384 in words is "eighty-one million, six hundred twenty-eight thousand, three hundred eighty-four".