81156155648 has 18 divisors (see below), whose sum is σ = 161995295574. Its totient is φ = 40578077696.

The previous prime is 81156155621. The next prime is 81156155693. The reversal of 81156155648 is 84655165118.

It can be written as a sum of positive squares in only one way, i.e., 81083701504 + 72454144 = 284752^2 + 8512^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81156155596 and 81156155605.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 158507861 + ... + 158508372.

It is an arithmetic number, because the mean of its divisors is an integer number (8999738643).

Almost surely, 2^81156155648 is an apocalyptic number.

It is an amenable number.

81156155648 is a deficient number, since it is larger than the sum of its proper divisors (80839139926).

81156155648 is an equidigital number, since it uses as much as digits as its factorization.

81156155648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 317016249 (or 317016235 counting only the distinct ones).

The product of its digits is 1152000, while the sum is 50.

The spelling of 81156155648 in words is "eighty-one billion, one hundred fifty-six million, one hundred fifty-five thousand, six hundred forty-eight".