205252491 has 4 divisors (see below), whose sum is σ = 273669992. Its totient is φ = 136834992.

The previous prime is 205252477. The next prime is 205252493. The reversal of 205252491 is 194252502.

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

It is not a de Polignac number, because 205252491 - 2⁶ = 205252427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205252493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34208746 + ... + 34208751.

It is an arithmetic number, because the mean of its divisors is an integer number (68417498).

Almost surely, 2^205252491 is an apocalyptic number.

205252491 is a deficient number, since it is larger than the sum of its proper divisors (68417501).

205252491 is an equidigital number, since it uses as much as digits as its factorization.

205252491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68417500.

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 205252491 is about 14326.6357181301. The cubic root of 205252491 is about 589.8788327258.

The spelling of 205252491 in words is "two hundred five million, two hundred fifty-two thousand, four hundred ninety-one".