81645514448 has 20 divisors (see below), whose sum is σ = 165065932128. Its totient is φ = 39047854560.

The previous prime is 81645514439. The next prime is 81645514481. The reversal of 81645514448 is 84441554618.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 81645514396 and 81645514405.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 110931038 + ... + 110931773.

Almost surely, 2^81645514448 is an apocalyptic number.

It is an amenable number.

81645514448 is an abundant number, since it is smaller than the sum of its proper divisors (83420417680).

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

81645514448 is a wasteful number, since it uses less digits than its factorization.

81645514448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221862842 (or 221862836 counting only the distinct ones).

The product of its digits is 2457600, while the sum is 50.

The spelling of 81645514448 in words is "eighty-one billion, six hundred forty-five million, five hundred fourteen thousand, four hundred forty-eight".