205724261 has 2 divisors, whose sum is σ = 205724262. Its totient is φ = 205724260.

The previous prime is 205724257. The next prime is 205724287. The reversal of 205724261 is 162427502.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 107516161 + 98208100 = 10369^2 + 9910^2 .

It is a cyclic number.

It is not a de Polignac number, because 205724261 - 2² = 205724257 is a prime.

It is a super-2 number, since 2×205724261² = 84644943127992242, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205724201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102862130 + 102862131.

It is an arithmetic number, because the mean of its divisors is an integer number (102862131).

Almost surely, 2^205724261 is an apocalyptic number.

It is an amenable number.

205724261 is a deficient number, since it is larger than the sum of its proper divisors (1).

205724261 is an equidigital number, since it uses as much as digits as its factorization.

205724261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6720, while the sum is 29.

The square root of 205724261 is about 14343.0910545809. The cubic root of 205724261 is about 590.3304296741.

The spelling of 205724261 in words is "two hundred five million, seven hundred twenty-four thousand, two hundred sixty-one".