81930684 has 96 divisors (see below), whose sum is σ = 228614400. Its totient is φ = 22543360.

The previous prime is 81930683. The next prime is 81930689. The reversal of 81930684 is 48603918.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81930683) 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 31 ways as a sum of consecutive naturals, for example, 64447 + ... + 65705.

It is an arithmetic number, because the mean of its divisors is an integer number (2381400).

Almost surely, 2^81930684 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 81930684, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114307200).

81930684 is an abundant number, since it is smaller than the sum of its proper divisors (146683716).

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

81930684 is a wasteful number, since it uses less digits than its factorization.

81930684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1323 (or 1321 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 39.

The square root of 81930684 is about 9051.5569931366. The cubic root of 81930684 is about 434.3256985882.

The spelling of 81930684 in words is "eighty-one million, nine hundred thirty thousand, six hundred eighty-four".