81445783 has 16 divisors (see below), whose sum is σ = 88335360. Its totient is φ = 74896096.

The previous prime is 81445753. The next prime is 81445817. The reversal of 81445783 is 38754418.

It is not a de Polignac number, because 81445783 - 2⁵ = 81445751 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81445753) 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, 63141 + ... + 64417.

It is an arithmetic number, because the mean of its divisors is an integer number (5520960).

Almost surely, 2^81445783 is an apocalyptic number.

81445783 is a deficient number, since it is larger than the sum of its proper divisors (6889577).

81445783 is a wasteful number, since it uses less digits than its factorization.

81445783 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1406.

The product of its digits is 107520, while the sum is 40.

The square root of 81445783 is about 9024.7317411655. The cubic root of 81445783 is about 433.4671605722.

It can be divided in two parts, 81445 and 783, that added together give a palindrome (82228).

The spelling of 81445783 in words is "eighty-one million, four hundred forty-five thousand, seven hundred eighty-three".