1123201331981 has 2 divisors, whose sum is σ = 1123201331982. Its totient is φ = 1123201331980.

The previous prime is 1123201331971. The next prime is 1123201332031. The reversal of 1123201331981 is 1891331023211.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 842523887881 + 280677444100 = 917891^2 + 529790^2 .

It is a cyclic number.

It is not a de Polignac number, because 1123201331981 - 2¹⁴ = 1123201315597 is a prime.

It is a super-2 number, since 2×1123201331981² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1123201331921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 561600665990 + 561600665991.

It is an arithmetic number, because the mean of its divisors is an integer number (561600665991).

Almost surely, 2^{1123201331981} is an apocalyptic number.

It is an amenable number.

1123201331981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1123201331981 is an equidigital number, since it uses as much as digits as its factorization.

1123201331981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 35.

The spelling of 1123201331981 in words is "one trillion, one hundred twenty-three billion, two hundred one million, three hundred thirty-one thousand, nine hundred eighty-one".