81799125648 has 20 divisors (see below), whose sum is σ = 211314408048. Its totient is φ = 27266375200.

The previous prime is 81799125613. The next prime is 81799125649. The reversal of 81799125648 is 84652199718.

It is a junction number, because it is equal to n+sod(n) for n = 81799125591 and 81799125600.

It is not an unprimeable number, because it can be changed into a prime (81799125649) 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 3 ways as a sum of consecutive naturals, for example, 852074178 + ... + 852074273.

Almost surely, 2^81799125648 is an apocalyptic number.

It is an amenable number.

81799125648 is an abundant number, since it is smaller than the sum of its proper divisors (129515282400).

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

81799125648 is a wasteful number, since it uses less digits than its factorization.

81799125648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1704148462 (or 1704148456 counting only the distinct ones).

The product of its digits is 8709120, while the sum is 60.

The spelling of 81799125648 in words is "eighty-one billion, seven hundred ninety-nine million, one hundred twenty-five thousand, six hundred forty-eight".