205345139 has 4 divisors (see below), whose sum is σ = 205622256. Its totient is φ = 205068024.

The previous prime is 205345121. The next prime is 205345163. The reversal of 205345139 is 931543502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 931543502 = 2 ⋅465771751.

It is a cyclic number.

It is not a de Polignac number, because 205345139 - 2²⁴ = 188567923 is a prime.

It is a super-2 number, since 2×205345139² = 84333252221858642, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205345199) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 137444 + ... + 138929.

It is an arithmetic number, because the mean of its divisors is an integer number (51405564).

Almost surely, 2^205345139 is an apocalyptic number.

205345139 is a deficient number, since it is larger than the sum of its proper divisors (277117).

205345139 is an equidigital number, since it uses as much as digits as its factorization.

205345139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277116.

The product of its (nonzero) digits is 16200, while the sum is 32.

The square root of 205345139 is about 14329.8687712065. The cubic root of 205345139 is about 589.9675736272.

The spelling of 205345139 in words is "two hundred five million, three hundred forty-five thousand, one hundred thirty-nine".