1281832109681 has 2 divisors, whose sum is σ = 1281832109682. Its totient is φ = 1281832109680.

The previous prime is 1281832109647. The next prime is 1281832109687. The reversal of 1281832109681 is 1869012381821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1240140595456 + 41691514225 = 1113616^2 + 204185^2 .

It is a cyclic number.

It is not a de Polignac number, because 1281832109681 - 2¹⁰ = 1281832108657 is a prime.

It is a super-2 number, since 2×1281832109681² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1281832109687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 640916054840 + 640916054841.

It is an arithmetic number, because the mean of its divisors is an integer number (640916054841).

Almost surely, 2^{1281832109681} is an apocalyptic number.

It is an amenable number.

1281832109681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1281832109681 is an equidigital number, since it uses as much as digits as its factorization.

1281832109681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 331776, while the sum is 50.

The spelling of 1281832109681 in words is "one trillion, two hundred eighty-one billion, eight hundred thirty-two million, one hundred nine thousand, six hundred eighty-one".