81085241 has 4 divisors (see below), whose sum is σ = 83276772. Its totient is φ = 78893712.

The previous prime is 81085237. The next prime is 81085271. The reversal of 81085241 is 14258018.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 71910400 + 9174841 = 8480^2 + 3029^2 .

It is a cyclic number.

It is not a de Polignac number, because 81085241 - 2² = 81085237 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81085211) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1095710 + ... + 1095783.

It is an arithmetic number, because the mean of its divisors is an integer number (20819193).

Almost surely, 2^81085241 is an apocalyptic number.

It is an amenable number.

81085241 is a deficient number, since it is larger than the sum of its proper divisors (2191531).

81085241 is a wasteful number, since it uses less digits than its factorization.

81085241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2191530.

The product of its (nonzero) digits is 2560, while the sum is 29.

The square root of 81085241 is about 9004.7343658767. The cubic root of 81085241 is about 432.8265941732.

The spelling of 81085241 in words is "eighty-one million, eighty-five thousand, two hundred forty-one".