1843555537981 has 2 divisors, whose sum is σ = 1843555537982. Its totient is φ = 1843555537980.

The previous prime is 1843555537937. The next prime is 1843555538057. The reversal of 1843555537981 is 1897355553481.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1688765225625 + 154790312356 = 1299525^2 + 393434^2 .

It is an emirp because it is prime and its reverse (1897355553481) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1843555537981 - 2⁷ = 1843555537853 is a prime.

It is a super-2 number, since 2×1843555537981² (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 (1843555537921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 921777768990 + 921777768991.

It is an arithmetic number, because the mean of its divisors is an integer number (921777768991).

Almost surely, 2^{1843555537981} is an apocalyptic number.

It is an amenable number.

1843555537981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1843555537981 is an equidigital number, since it uses as much as digits as its factorization.

1843555537981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720000, while the sum is 64.

The spelling of 1843555537981 in words is "one trillion, eight hundred forty-three billion, five hundred fifty-five million, five hundred thirty-seven thousand, nine hundred eighty-one".