205121547 has 12 divisors (see below), whose sum is σ = 297359920. Its totient is φ = 136252368.

The previous prime is 205121537. The next prime is 205121551. The reversal of 205121547 is 745121502.

It is not a de Polignac number, because 205121547 - 2⁷ = 205121419 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 205121547.

It is not an unprimeable number, because it can be changed into a prime (205121537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38647 + ... + 43632.

Almost surely, 2^205121547 is an apocalyptic number.

205121547 is a deficient number, since it is larger than the sum of its proper divisors (92238373).

205121547 is a wasteful number, since it uses less digits than its factorization.

205121547 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82562 (or 82559 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 27.

The square root of 205121547 is about 14322.0650396512. The cubic root of 205121547 is about 589.7533652669.

The spelling of 205121547 in words is "two hundred five million, one hundred twenty-one thousand, five hundred forty-seven".