81442563532 has 24 divisors (see below), whose sum is σ = 155524057920. Its totient is φ = 37009156560.

The previous prime is 81442563523. The next prime is 81442563533. The reversal of 81442563532 is 23536524418.

It is not an unprimeable number, because it can be changed into a prime (81442563533) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 91938 + ... + 413929.

It is an arithmetic number, because the mean of its divisors is an integer number (6480169080).

Almost surely, 2^81442563532 is an apocalyptic number.

It is an amenable number.

81442563532 is a deficient number, since it is larger than the sum of its proper divisors (74081494388).

81442563532 is a wasteful number, since it uses less digits than its factorization.

81442563532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 509541 (or 509539 counting only the distinct ones).

The product of its digits is 691200, while the sum is 43.

The spelling of 81442563532 in words is "eighty-one billion, four hundred forty-two million, five hundred sixty-three thousand, five hundred thirty-two".