81100250 has 96 divisors (see below), whose sum is σ = 191213568. Its totient is φ = 25212000.

The previous prime is 81100237. The next prime is 81100259. The reversal of 81100250 is 5200118.

It is not an unprimeable number, because it can be changed into a prime (81100259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 211559 + ... + 211941.

It is an arithmetic number, because the mean of its divisors is an integer number (1991808).

Almost surely, 2^81100250 is an apocalyptic number.

81100250 is an abundant number, since it is smaller than the sum of its proper divisors (110113318).

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

81100250 is a wasteful number, since it uses less digits than its factorization.

81100250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 429 (or 408 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 17.

The square root of 81100250 is about 9005.5677222483. The cubic root of 81100250 is about 432.8532981434.

Adding to 81100250 its reverse (5200118), we get a palindrome (86300368).

The spelling of 81100250 in words is "eighty-one million, one hundred thousand, two hundred fifty".