81633328 has 20 divisors (see below), whose sum is σ = 180759760. Its totient is φ = 34985664.

The previous prime is 81633319. The next prime is 81633373. The reversal of 81633328 is 82333618.

It is a junction number, because it is equal to n+sod(n) for n = 81633293 and 81633302.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 364323 + ... + 364546.

It is an arithmetic number, because the mean of its divisors is an integer number (9037988).

Almost surely, 2^81633328 is an apocalyptic number.

It is an amenable number.

81633328 is an abundant number, since it is smaller than the sum of its proper divisors (99126432).

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

81633328 is a wasteful number, since it uses less digits than its factorization.

81633328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 728884 (or 728878 counting only the distinct ones).

The product of its digits is 20736, while the sum is 34.

The square root of 81633328 is about 9035.1163799920. The cubic root of 81633328 is about 433.7996200988.

The spelling of 81633328 in words is "eighty-one million, six hundred thirty-three thousand, three hundred twenty-eight".