205713773261 has 2 divisors, whose sum is σ = 205713773262. Its totient is φ = 205713773260.

The previous prime is 205713773201. The next prime is 205713773263. The reversal of 205713773261 is 162377317502.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 203406412036 + 2307361225 = 451006^2 + 48035^2 .

It is a cyclic number.

It is not a de Polignac number, because 205713773261 - 2¹⁸ = 205713511117 is a prime.

Together with 205713773263, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205713773263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102856886630 + 102856886631.

It is an arithmetic number, because the mean of its divisors is an integer number (102856886631).

Almost surely, 2^205713773261 is an apocalyptic number.

It is an amenable number.

205713773261 is a deficient number, since it is larger than the sum of its proper divisors (1).

205713773261 is an equidigital number, since it uses as much as digits as its factorization.

205713773261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 370440, while the sum is 44.

The spelling of 205713773261 in words is "two hundred five billion, seven hundred thirteen million, seven hundred seventy-three thousand, two hundred sixty-one".