205211230409 has 2 divisors, whose sum is σ = 205211230410. Its totient is φ = 205211230408.

The previous prime is 205211230397. The next prime is 205211230417. The reversal of 205211230409 is 904032112502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 198356218384 + 6855012025 = 445372^2 + 82795^2 .

It is a cyclic number.

It is not a de Polignac number, because 205211230409 - 2⁸ = 205211230153 is a prime.

It is a super-2 number, since 2×205211230409² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (205211230489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102605615204 + 102605615205.

It is an arithmetic number, because the mean of its divisors is an integer number (102605615205).

Almost surely, 2^205211230409 is an apocalyptic number.

It is an amenable number.

205211230409 is a deficient number, since it is larger than the sum of its proper divisors (1).

205211230409 is an equidigital number, since it uses as much as digits as its factorization.

205211230409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 29.

The spelling of 205211230409 in words is "two hundred five billion, two hundred eleven million, two hundred thirty thousand, four hundred nine".