81895825 has 18 divisors (see below), whose sum is σ = 111626102. Its totient is φ = 59558400.

The previous prime is 81895813. The next prime is 81895841. The reversal of 81895825 is 52859818.

It can be written as a sum of positive squares in 3 ways, for example, as 5035536 + 76860289 = 2244^2 + 8767^2 .

It is not a de Polignac number, because 81895825 - 2¹³ = 81887633 is a prime.

It is a Duffinian number.

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 17 ways as a sum of consecutive naturals, for example, 10512 + ... + 16561.

Almost surely, 2^81895825 is an apocalyptic number.

It is an amenable number.

81895825 is a deficient number, since it is larger than the sum of its proper divisors (29730277).

81895825 is a wasteful number, since it uses less digits than its factorization.

81895825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27105 (or 27089 counting only the distinct ones).

The product of its digits is 230400, while the sum is 46.

The square root of 81895825 is about 9049.6312079554. The cubic root of 81895825 is about 434.2640924169.

The spelling of 81895825 in words is "eighty-one million, eight hundred ninety-five thousand, eight hundred twenty-five".