205421523389 has 2 divisors, whose sum is σ = 205421523390. Its totient is φ = 205421523388.

The previous prime is 205421523367. The next prime is 205421523421. The reversal of 205421523389 is 983325124502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 166786476025 + 38635047364 = 408395^2 + 196558^2 .

It is a cyclic number.

It is not a de Polignac number, because 205421523389 - 2¹² = 205421519293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205421523889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102710761694 + 102710761695.

It is an arithmetic number, because the mean of its divisors is an integer number (102710761695).

Almost surely, 2^205421523389 is an apocalyptic number.

It is an amenable number.

205421523389 is a deficient number, since it is larger than the sum of its proper divisors (1).

205421523389 is an equidigital number, since it uses as much as digits as its factorization.

205421523389 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 518400, while the sum is 44.

The spelling of 205421523389 in words is "two hundred five billion, four hundred twenty-one million, five hundred twenty-three thousand, three hundred eighty-nine".