205109489 has 16 divisors (see below), whose sum is σ = 231109200. Its totient is φ = 180719616.

The previous prime is 205109479. The next prime is 205109501. The reversal of 205109489 is 984901502.

It can be written as a sum of positive squares in 8 ways, for example, as 20611600 + 184497889 = 4540^2 + 13583^2 .

It is a cyclic number.

It is not a de Polignac number, because 205109489 - 2⁴ = 205109473 is a prime.

It is a super-2 number, since 2×205109489² = 84139804955682242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205109449) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30497 + ... + 36609.

It is an arithmetic number, because the mean of its divisors is an integer number (14444325).

Almost surely, 2^205109489 is an apocalyptic number.

205109489 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

205109489 is a deficient number, since it is larger than the sum of its proper divisors (25999711).

205109489 is a wasteful number, since it uses less digits than its factorization.

205109489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6244.

The product of its (nonzero) digits is 25920, while the sum is 38.

The square root of 205109489 is about 14321.6440746166. The cubic root of 205109489 is about 589.7418088905.

The spelling of 205109489 in words is "two hundred five million, one hundred nine thousand, four hundred eighty-nine".