1205249845981 has 2 divisors, whose sum is σ = 1205249845982. Its totient is φ = 1205249845980.

The previous prime is 1205249845951. The next prime is 1205249846023. The reversal of 1205249845981 is 1895489425021.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1025105625625 + 180144220356 = 1012475^2 + 424434^2 .

It is a cyclic number.

It is not a de Polignac number, because 1205249845981 - 2¹⁷ = 1205249714909 is a prime.

It is a super-2 number, since 2×1205249845981² (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 (1205249845951) 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, 602624922990 + 602624922991.

It is an arithmetic number, because the mean of its divisors is an integer number (602624922991).

Almost surely, 2^{1205249845981} is an apocalyptic number.

It is an amenable number.

1205249845981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1205249845981 is an equidigital number, since it uses as much as digits as its factorization.

1205249845981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8294400, while the sum is 58.

The spelling of 1205249845981 in words is "one trillion, two hundred five billion, two hundred forty-nine million, eight hundred forty-five thousand, nine hundred eighty-one".