81241845 has 16 divisors (see below), whose sum is σ = 132440832. Its totient is φ = 42511040.

The previous prime is 81241843. The next prime is 81241871. The reversal of 81241845 is 54814218.

It is not a de Polignac number, because 81241845 - 2¹ = 81241843 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81241843) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 50301 + ... + 51890.

It is an arithmetic number, because the mean of its divisors is an integer number (8277552).

Almost surely, 2^81241845 is an apocalyptic number.

It is an amenable number.

81241845 is a deficient number, since it is larger than the sum of its proper divisors (51198987).

81241845 is a wasteful number, since it uses less digits than its factorization.

81241845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102252.

The product of its digits is 10240, while the sum is 33.

The square root of 81241845 is about 9013.4258192987. The cubic root of 81241845 is about 433.1050615602.

The spelling of 81241845 in words is "eighty-one million, two hundred forty-one thousand, eight hundred forty-five".