205161499649 has 2 divisors, whose sum is σ = 205161499650. Its totient is φ = 205161499648.

The previous prime is 205161499589. The next prime is 205161499663. The reversal of 205161499649 is 946994161502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 115425306049 + 89736193600 = 339743^2 + 299560^2 .

It is a cyclic number.

It is not a de Polignac number, because 205161499649 - 2²⁰ = 205160451073 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 205161499594 and 205161499603.

It is not a weakly prime, because it can be changed into another prime (205161499349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102580749824 + 102580749825.

It is an arithmetic number, because the mean of its divisors is an integer number (102580749825).

Almost surely, 2^205161499649 is an apocalyptic number.

It is an amenable number.

205161499649 is a deficient number, since it is larger than the sum of its proper divisors (1).

205161499649 is an equidigital number, since it uses as much as digits as its factorization.

205161499649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4199040, while the sum is 56.

The spelling of 205161499649 in words is "two hundred five billion, one hundred sixty-one million, four hundred ninety-nine thousand, six hundred forty-nine".