81975500 has 48 divisors (see below), whose sum is σ = 188479200. Its totient is φ = 31060800.

The previous prime is 81975499. The next prime is 81975503. The reversal of 81975500 is 557918.

It is not an unprimeable number, because it can be changed into a prime (81975503) 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 15 ways as a sum of consecutive naturals, for example, 5186 + ... + 13814.

It is an arithmetic number, because the mean of its divisors is an integer number (3926650).

Almost surely, 2^81975500 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 81975500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94239600).

81975500 is an abundant number, since it is smaller than the sum of its proper divisors (106503700).

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

81975500 is a wasteful number, since it uses less digits than its factorization.

81975500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8667 (or 8655 counting only the distinct ones).

The product of its (nonzero) digits is 12600, while the sum is 35.

The square root of 81975500 is about 9054.0322508814. The cubic root of 81975500 is about 434.4048760570.

The spelling of 81975500 in words is "eighty-one million, nine hundred seventy-five thousand, five hundred".