81693836 has 12 divisors (see below), whose sum is σ = 163387728. Its totient is φ = 35011632.

The previous prime is 81693811. The next prime is 81693847. The reversal of 81693836 is 63839618.

81693836 is an admirable number.

It is a hoax number, since the sum of its digits (44) coincides with the sum of the digits of its distinct prime factors.

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 in 3 ways as a sum of consecutive naturals, for example, 1458791 + ... + 1458846.

It is an arithmetic number, because the mean of its divisors is an integer number (13615644).

Almost surely, 2^81693836 is an apocalyptic number.

It is an amenable number.

81693836 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

81693836 is a wasteful number, since it uses less digits than its factorization.

81693836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2917648 (or 2917646 counting only the distinct ones).

The product of its digits is 186624, while the sum is 44.

The square root of 81693836 is about 9038.4642500814. The cubic root of 81693836 is about 433.9067734943.

The spelling of 81693836 in words is "eighty-one million, six hundred ninety-three thousand, eight hundred thirty-six".