81444807 has 24 divisors (see below), whose sum is σ = 127938096. Its totient is φ = 49718016.

The previous prime is 81444793. The next prime is 81444809. The reversal of 81444807 is 70844418.

It is a happy number.

It is not a de Polignac number, because 81444807 - 2⁸ = 81444551 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81444809) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1533 + ... + 12854.

It is an arithmetic number, because the mean of its divisors is an integer number (5330754).

Almost surely, 2^81444807 is an apocalyptic number.

81444807 is a deficient number, since it is larger than the sum of its proper divisors (46493289).

81444807 is a wasteful number, since it uses less digits than its factorization.

81444807 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14447 (or 14444 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 36.

The square root of 81444807 is about 9024.6776673741. The cubic root of 81444807 is about 433.4654290906.

The spelling of 81444807 in words is "eighty-one million, four hundred forty-four thousand, eight hundred seven".