81085025 has 12 divisors (see below), whose sum is σ = 114909312. Its totient is φ = 55601040.

The previous prime is 81085009. The next prime is 81085033. The reversal of 81085025 is 52058018.

It is not a de Polignac number, because 81085025 - 2⁴ = 81085009 is a prime.

It is a congruent 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 11 ways as a sum of consecutive naturals, for example, 231497 + ... + 231846.

It is an arithmetic number, because the mean of its divisors is an integer number (9575776).

Almost surely, 2^81085025 is an apocalyptic number.

It is an amenable number.

81085025 is a deficient number, since it is larger than the sum of its proper divisors (33824287).

81085025 is a wasteful number, since it uses less digits than its factorization.

81085025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 463360 (or 463355 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 29.

The square root of 81085025 is about 9004.7223721778. The cubic root of 81085025 is about 432.8262098426.

The spelling of 81085025 in words is "eighty-one million, eighty-five thousand, twenty-five".