81336684 has 144 divisors (see below), whose sum is σ = 233569280. Its totient is φ = 21859200.

The previous prime is 81336683. The next prime is 81336691. The reversal of 81336684 is 48663318.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (81336683) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 585087 + ... + 585225.

Almost surely, 2^81336684 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81336684, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116784640).

81336684 is an abundant number, since it is smaller than the sum of its proper divisors (152232596).

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

81336684 is a wasteful number, since it uses less digits than its factorization.

81336684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212 (or 199 counting only the distinct ones).

The product of its digits is 82944, while the sum is 39.

The square root of 81336684 is about 9018.6852700380. The cubic root of 81336684 is about 433.2735267889.

It can be divided in two parts, 813366 and 84, that added together give a triangular number (813450 = T₁₂₇₅).

The spelling of 81336684 in words is "eighty-one million, three hundred thirty-six thousand, six hundred eighty-four".