81556445050 has 24 divisors (see below), whose sum is σ = 154557162396. Its totient is φ = 32007056640.

The previous prime is 81556445029. The next prime is 81556445051. The reversal of 81556445050 is 5054465518.

It can be written as a sum of positive squares in 6 ways, for example, as 26219057929 + 55337387121 = 161923^2 + 235239^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81556444988 and 81556445006.

It is not an unprimeable number, because it can be changed into a prime (81556445051) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15385359 + ... + 15390658.

Almost surely, 2^81556445050 is an apocalyptic number.

81556445050 is a deficient number, since it is larger than the sum of its proper divisors (73000717346).

81556445050 is a wasteful number, since it uses less digits than its factorization.

81556445050 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30776082 (or 30776077 counting only the distinct ones).

The product of its (nonzero) digits is 480000, while the sum is 43.

The spelling of 81556445050 in words is "eighty-one billion, five hundred fifty-six million, four hundred forty-five thousand, fifty".