205813381 has 2 divisors, whose sum is σ = 205813382. Its totient is φ = 205813380.

The previous prime is 205813337. The next prime is 205813397. The reversal of 205813381 is 183318502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 200477281 + 5336100 = 14159^2 + 2310^2 .

It is a cyclic number.

It is not a de Polignac number, because 205813381 - 2²¹ = 203716229 is a prime.

It is a super-2 number, since 2×205813381² = 84718295597302322, 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 (205813081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102906690 + 102906691.

It is an arithmetic number, because the mean of its divisors is an integer number (102906691).

Almost surely, 2^205813381 is an apocalyptic number.

It is an amenable number.

205813381 is a deficient number, since it is larger than the sum of its proper divisors (1).

205813381 is an equidigital number, since it uses as much as digits as its factorization.

205813381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 205813381 is about 14346.1974404370. The cubic root of 205813381 is about 590.4156613211.

The spelling of 205813381 in words is "two hundred five million, eight hundred thirteen thousand, three hundred eighty-one".