205172049291 has 24 divisors (see below), whose sum is σ = 300788850432. Its totient is φ = 124307026800.

The previous prime is 205172049289. The next prime is 205172049307. The reversal of 205172049291 is 192940271502.

205172049291 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 205172049291 - 2¹ = 205172049289 is a prime.

It is not an unprimeable number, because it can be changed into a prime (205172049281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1069770 + ... + 1246896.

It is an arithmetic number, because the mean of its divisors is an integer number (12532868768).

Almost surely, 2^205172049291 is an apocalyptic number.

205172049291 is a deficient number, since it is larger than the sum of its proper divisors (95616801141).

205172049291 is a wasteful number, since it uses less digits than its factorization.

205172049291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180343 (or 180332 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 42.

The spelling of 205172049291 in words is "two hundred five billion, one hundred seventy-two million, forty-nine thousand, two hundred ninety-one".