81444012 has 48 divisors (see below), whose sum is σ = 213561600. Its totient is φ = 23969088.

The previous prime is 81444007. The next prime is 81444017. The reversal of 81444012 is 21044418.

It is an interprime number because it is at equal distance from previous prime (81444007) and next prime (81444017).

It is a super-2 number, since 2×81444012² = 13266254181312288, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81444017) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7762 + ... + 14937.

It is an arithmetic number, because the mean of its divisors is an integer number (4449200).

Almost surely, 2^81444012 is an apocalyptic number.

It is an amenable number.

81444012 is an abundant number, since it is smaller than the sum of its proper divisors (132117588).

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

81444012 is a wasteful number, since it uses less digits than its factorization.

81444012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22742 (or 22740 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 24.

The square root of 81444012 is about 9024.6336213721. The cubic root of 81444012 is about 433.4640187034.

The spelling of 81444012 in words is "eighty-one million, four hundred forty-four thousand, twelve".