1281444376081 has 3 divisors (see below), whose sum is σ = 1281445508091. Its totient is φ = 1281443244072.

The previous prime is 1281444376013. The next prime is 1281444376087. The reversal of 1281444376081 is 1806734441821.

The square root of 1281444376081 is 1132009.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 77947614481 + 1203496761600 = 279191^2 + 1097040^2 .

It is not a de Polignac number, because 1281444376081 - 2²⁷ = 1281310158353 is a prime.

It is a super-2 number, since 2×1281444376081² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1281444376087) 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 2 ways as a sum of consecutive naturals, for example, 566005 + ... + 1698013.

It is an arithmetic number, because the mean of its divisors is an integer number (427148502697).

Almost surely, 2^{1281444376081} is an apocalyptic number.

1281444376081 is the 1132009-th square number.

1281444376081 is the 566005-th centered octagonal number.

It is an amenable number.

1281444376081 is a deficient number, since it is larger than the sum of its proper divisors (1132010).

1281444376081 is an frugal number, since it uses more digits than its factorization.

1281444376081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2264018 (or 1132009 counting only the distinct ones).

The product of its (nonzero) digits is 1032192, while the sum is 49.

Multiplying 1281444376081 by its sum of digits (49), we get a square (62790774427969 = 7924063²).

The spelling of 1281444376081 in words is "one trillion, two hundred eighty-one billion, four hundred forty-four million, three hundred seventy-six thousand, eighty-one".