205397794577 has 2 divisors, whose sum is σ = 205397794578. Its totient is φ = 205397794576.

The previous prime is 205397794549. The next prime is 205397794583. The reversal of 205397794577 is 775497793502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 181006851601 + 24390942976 = 425449^2 + 156176^2 .

It is a cyclic number.

It is not a de Polignac number, because 205397794577 - 2⁶ = 205397794513 is a prime.

It is not a weakly prime, because it can be changed into another prime (205397794507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102698897288 + 102698897289.

It is an arithmetic number, because the mean of its divisors is an integer number (102698897289).

Almost surely, 2^205397794577 is an apocalyptic number.

It is an amenable number.

205397794577 is a deficient number, since it is larger than the sum of its proper divisors (1).

205397794577 is an equidigital number, since it uses as much as digits as its factorization.

205397794577 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 116688600, while the sum is 65.

The spelling of 205397794577 in words is "two hundred five billion, three hundred ninety-seven million, seven hundred ninety-four thousand, five hundred seventy-seven".