81837810 has 64 divisors (see below), whose sum is σ = 222912000. Its totient is φ = 21355776.

The previous prime is 81837809. The next prime is 81837817. The reversal of 81837810 is 1873818.

It is a super-2 number, since 2×81837810² = 13394854291192200, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81837817) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9466 + ... + 15914.

It is an arithmetic number, because the mean of its divisors is an integer number (3483000).

Almost surely, 2^81837810 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81837810, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111456000).

81837810 is an abundant number, since it is smaller than the sum of its proper divisors (141074190).

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

81837810 is a wasteful number, since it uses less digits than its factorization.

81837810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6512 (or 6506 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 36.

The square root of 81837810 is about 9046.4252608420. The cubic root of 81837810 is about 434.1615239699.

The spelling of 81837810 in words is "eighty-one million, eight hundred thirty-seven thousand, eight hundred ten".