81085551056 has 10 divisors (see below), whose sum is σ = 157103255202. Its totient is φ = 40542775520.

The previous prime is 81085551037. The next prime is 81085551061. The reversal of 81085551056 is 65015558018.

It can be written as a sum of positive squares in only one way, i.e., 76961856400 + 4123694656 = 277420^2 + 64216^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81085550998 and 81085551016.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2533923455 + ... + 2533923486.

Almost surely, 2^81085551056 is an apocalyptic number.

It is an amenable number.

81085551056 is a deficient number, since it is larger than the sum of its proper divisors (76017704146).

81085551056 is a wasteful number, since it uses less digits than its factorization.

81085551056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5067846949 (or 5067846943 counting only the distinct ones).

The product of its (nonzero) digits is 240000, while the sum is 44.

The spelling of 81085551056 in words is "eighty-one billion, eighty-five million, five hundred fifty-one thousand, fifty-six".