81237600 has 144 divisors (see below), whose sum is σ = 293887440. Its totient is φ = 21657600.

The previous prime is 81237599. The next prime is 81237619. The reversal of 81237600 is 673218.

It is a tau number, because it is divible by the number of its divisors (144).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 19720 + ... + 23480.

It is an arithmetic number, because the mean of its divisors is an integer number (2040885).

Almost surely, 2^81237600 is an apocalyptic number.

81237600 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81237600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (146943720).

81237600 is an abundant number, since it is smaller than the sum of its proper divisors (212649840).

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

81237600 is a wasteful number, since it uses less digits than its factorization.

81237600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3790 (or 3771 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 81237600 is about 9013.1903341714. The cubic root of 81237600 is about 433.0975179804.

The spelling of 81237600 in words is "eighty-one million, two hundred thirty-seven thousand, six hundred".