1016571071981 has 2 divisors, whose sum is σ = 1016571071982. Its totient is φ = 1016571071980.

The previous prime is 1016571071977. The next prime is 1016571072073. The reversal of 1016571071981 is 1891701756101.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 509960233225 + 506610838756 = 714115^2 + 711766^2 .

It is a cyclic number.

It is not a de Polignac number, because 1016571071981 - 2² = 1016571071977 is a prime.

It is a super-2 number, since 2×1016571071981² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1016501071981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 508285535990 + 508285535991.

It is an arithmetic number, because the mean of its divisors is an integer number (508285535991).

Almost surely, 2^{1016571071981} is an apocalyptic number.

It is an amenable number.

1016571071981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1016571071981 is an equidigital number, since it uses as much as digits as its factorization.

1016571071981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 105840, while the sum is 47.

The spelling of 1016571071981 in words is "one trillion, sixteen billion, five hundred seventy-one million, seventy-one thousand, nine hundred eighty-one".