81660250 has 32 divisors (see below), whose sum is σ = 174710016. Its totient is φ = 27997200.

The previous prime is 81660223. The next prime is 81660263. The reversal of 81660250 is 5206618.

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 15 ways as a sum of consecutive naturals, for example, 21582 + ... + 25081.

It is an arithmetic number, because the mean of its divisors is an integer number (5459688).

Almost surely, 2^81660250 is an apocalyptic number.

81660250 is an abundant number, since it is smaller than the sum of its proper divisors (93049766).

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

81660250 is a wasteful number, since it uses less digits than its factorization.

81660250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46687 (or 46677 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 81660250 is about 9036.6061107033. The cubic root of 81660250 is about 433.8473027061.

Adding to 81660250 its reverse (5206618), we get a palindrome (86866868).

The spelling of 81660250 in words is "eighty-one million, six hundred sixty thousand, two hundred fifty".