205001291 has 4 divisors (see below), whose sum is σ = 223637784. Its totient is φ = 186364800.

The previous prime is 205001281. The next prime is 205001309. The reversal of 205001291 is 192100502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 205001291 - 2¹⁰ = 205000267 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205001281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9318230 + ... + 9318251.

It is an arithmetic number, because the mean of its divisors is an integer number (55909446).

Almost surely, 2^205001291 is an apocalyptic number.

205001291 is a deficient number, since it is larger than the sum of its proper divisors (18636493).

205001291 is a wasteful number, since it uses less digits than its factorization.

205001291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18636492.

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 205001291 is about 14317.8661468810. The cubic root of 205001291 is about 589.6380917525.

Adding to 205001291 its reverse (192100502), we get a palindrome (397101793).

The spelling of 205001291 in words is "two hundred five million, one thousand, two hundred ninety-one".