81081248057 has 8 divisors (see below), whose sum is σ = 82847809800. Its totient is φ = 79323454080.

The previous prime is 81081247981. The next prime is 81081248089. The reversal of 81081248057 is 75084218018.

It can be written as a sum of positive squares in 4 ways, for example, as 37535575081 + 43545672976 = 193741^2 + 208676^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81081248057 - 2¹⁸ = 81080985913 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81081247999 and 81081248017.

It is not an unprimeable number, because it can be changed into a prime (81081248257) 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 7 ways as a sum of consecutive naturals, for example, 2173244 + ... + 2210237.

It is an arithmetic number, because the mean of its divisors is an integer number (10355976225).

Almost surely, 2^81081248057 is an apocalyptic number.

It is an amenable number.

81081248057 is a deficient number, since it is larger than the sum of its proper divisors (1766561743).

81081248057 is a wasteful number, since it uses less digits than its factorization.

81081248057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4383883.

The product of its (nonzero) digits is 143360, while the sum is 44.

The spelling of 81081248057 in words is "eighty-one billion, eighty-one million, two hundred forty-eight thousand, fifty-seven".