81766250 has 20 divisors (see below), whose sum is σ = 153265002. Its totient is φ = 32706000.

The previous prime is 81766249. The next prime is 81766273. The reversal of 81766250 is 5266718.

It can be written as a sum of positive squares in 5 ways, for example, as 26569 + 81739681 = 163^2 + 9041^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81766250.

It is an unprimeable number.

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 9 ways as a sum of consecutive naturals, for example, 31457 + ... + 33956.

Almost surely, 2^81766250 is an apocalyptic number.

81766250 is a deficient number, since it is larger than the sum of its proper divisors (71498752).

81766250 is an equidigital number, since it uses as much as digits as its factorization.

81766250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65435 (or 65420 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 81766250 is about 9042.4692424138. The cubic root of 81766250 is about 434.0349416536.

The spelling of 81766250 in words is "eighty-one million, seven hundred sixty-six thousand, two hundred fifty".