205142521 has 2 divisors, whose sum is σ = 205142522. Its totient is φ = 205142520.

The previous prime is 205142513. The next prime is 205142569. The reversal of 205142521 is 125241502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 181279296 + 23863225 = 13464^2 + 4885^2 .

It is a cyclic number.

It is not a de Polignac number, because 205142521 - 2³ = 205142513 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 205142492 and 205142501.

It is not a weakly prime, because it can be changed into another prime (205142591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102571260 + 102571261.

It is an arithmetic number, because the mean of its divisors is an integer number (102571261).

Almost surely, 2^205142521 is an apocalyptic number.

It is an amenable number.

205142521 is a deficient number, since it is larger than the sum of its proper divisors (1).

205142521 is an equidigital number, since it uses as much as digits as its factorization.

205142521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 800, while the sum is 22.

The square root of 205142521 is about 14322.7972477446. The cubic root of 205142521 is about 589.7734656508.

The spelling of 205142521 in words is "two hundred five million, one hundred forty-two thousand, five hundred twenty-one".