205051261 has 2 divisors, whose sum is σ = 205051262. Its totient is φ = 205051260.

The previous prime is 205051247. The next prime is 205051303. The reversal of 205051261 is 162150502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 130988025 + 74063236 = 11445^2 + 8606^2 .

It is a cyclic number.

It is not a de Polignac number, because 205051261 - 2¹¹ = 205049213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205051201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102525630 + 102525631.

It is an arithmetic number, because the mean of its divisors is an integer number (102525631).

Almost surely, 2^205051261 is an apocalyptic number.

It is an amenable number.

205051261 is a deficient number, since it is larger than the sum of its proper divisors (1).

205051261 is an equidigital number, since it uses as much as digits as its factorization.

205051261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 600, while the sum is 22.

The square root of 205051261 is about 14319.6110631539. The cubic root of 205051261 is about 589.6859968520.

The spelling of 205051261 in words is "two hundred five million, fifty-one thousand, two hundred sixty-one".