81831960 has 144 divisors (see below), whose sum is σ = 309441600. Its totient is φ = 18700416.

The previous prime is 81831929. The next prime is 81832019. The reversal of 81831960 is 6913818.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 15321 + ... + 19959.

It is an arithmetic number, because the mean of its divisors is an integer number (2148900).

Almost surely, 2^81831960 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 81831960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (154720800).

81831960 is an abundant number, since it is smaller than the sum of its proper divisors (227609640).

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

81831960 is a wasteful number, since it uses less digits than its factorization.

81831960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4670 (or 4656 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 81831960 is about 9046.1019229279. The cubic root of 81831960 is about 434.1511786888.

The spelling of 81831960 in words is "eighty-one million, eight hundred thirty-one thousand, nine hundred sixty".