205421052203749 has 2 divisors, whose sum is σ = 205421052203750. Its totient is φ = 205421052203748.

The previous prime is 205421052203713. The next prime is 205421052203753. The reversal of 205421052203749 is 947302250124502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 184081669228900 + 21339382974849 = 13567670^2 + 4619457^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205421052203749 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 205421052203699 and 205421052203708.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205421052903749) 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, 102710526101874 + 102710526101875.

It is an arithmetic number, because the mean of its divisors is an integer number (102710526101875).

Almost surely, 2^{205421052203749} is an apocalyptic number.

It is an amenable number.

205421052203749 is a deficient number, since it is larger than the sum of its proper divisors (1).

205421052203749 is an equidigital number, since it uses as much as digits as its factorization.

205421052203749 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1209600, while the sum is 46.

The spelling of 205421052203749 in words is "two hundred five trillion, four hundred twenty-one billion, fifty-two million, two hundred three thousand, seven hundred forty-nine".