81038500 has 48 divisors (see below), whose sum is σ = 179957232. Its totient is φ = 31872000.

The previous prime is 81038497. The next prime is 81038521. The reversal of 81038500 is 583018.

It can be written as a sum of positive squares in 8 ways, for example, as 44169316 + 36869184 = 6646^2 + 6072^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29172 + ... + 31828.

It is an arithmetic number, because the mean of its divisors is an integer number (3749109).

Almost surely, 2^81038500 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 81038500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89978616).

81038500 is an abundant number, since it is smaller than the sum of its proper divisors (98918732).

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

81038500 is a wasteful number, since it uses less digits than its factorization.

81038500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2737 (or 2725 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 81038500 is about 9002.1386347912. The cubic root of 81038500 is about 432.7434116025.

The spelling of 81038500 in words is "eighty-one million, thirty-eight thousand, five hundred".