81242844 has 12 divisors (see below), whose sum is σ = 189566664. Its totient is φ = 27080944.

The previous prime is 81242839. The next prime is 81242851. The reversal of 81242844 is 44824218.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3385107 + ... + 3385130.

It is an arithmetic number, because the mean of its divisors is an integer number (15797222).

Almost surely, 2^81242844 is an apocalyptic number.

It is an amenable number.

81242844 is an abundant number, since it is smaller than the sum of its proper divisors (108323820).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81242844 is a wasteful number, since it uses less digits than its factorization.

81242844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6770244 (or 6770242 counting only the distinct ones).

The product of its digits is 16384, while the sum is 33.

The square root of 81242844 is about 9013.4812364591. The cubic root of 81242844 is about 433.1068367955.

The spelling of 81242844 in words is "eighty-one million, two hundred forty-two thousand, eight hundred forty-four".