81933536 has 24 divisors (see below), whose sum is σ = 164044440. Its totient is φ = 40271488.

The previous prime is 81933517. The next prime is 81933541. The reversal of 81933536 is 63533918.

It is a self number, because there is not a number n which added to its sum of digits gives 81933536.

It is a congruent number.

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, 19811 + ... + 23586.

It is an arithmetic number, because the mean of its divisors is an integer number (6835185).

Almost surely, 2^81933536 is an apocalyptic number.

It is an amenable number.

81933536 is an abundant number, since it is smaller than the sum of its proper divisors (82110904).

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

81933536 is a wasteful number, since it uses less digits than its factorization.

81933536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43466 (or 43458 counting only the distinct ones).

The product of its digits is 58320, while the sum is 38.

The square root of 81933536 is about 9051.7145337223. The cubic root of 81933536 is about 434.3307381430.

The spelling of 81933536 in words is "eighty-one million, nine hundred thirty-three thousand, five hundred thirty-six".