81444461 has 8 divisors (see below), whose sum is σ = 93169344. Its totient is φ = 69742080.

The previous prime is 81444439. The next prime is 81444479. The reversal of 81444461 is 16444418.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81444461 - 2¹⁴ = 81428077 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81444361) 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 7 ways as a sum of consecutive naturals, for example, 3026 + ... + 13116.

It is an arithmetic number, because the mean of its divisors is an integer number (11646168).

Almost surely, 2^81444461 is an apocalyptic number.

It is an amenable number.

81444461 is a deficient number, since it is larger than the sum of its proper divisors (11724883).

81444461 is a wasteful number, since it uses less digits than its factorization.

81444461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11251.

The product of its digits is 12288, while the sum is 32.

The square root of 81444461 is about 9024.6584976940. The cubic root of 81444461 is about 433.4648152628.

Adding to 81444461 its reverse (16444418), we get a palindrome (97888879).

The spelling of 81444461 in words is "eighty-one million, four hundred forty-four thousand, four hundred sixty-one".