205123239 has 8 divisors (see below), whose sum is σ = 303886320. Its totient is φ = 136748808.

The previous prime is 205123229. The next prime is 205123253. The reversal of 205123239 is 932321502.

It is not a de Polignac number, because 205123239 - 2¹⁶ = 205057703 is a prime.

It is a super-2 number, since 2×205123239² = 84151086355702242, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 7597157 = 205123239 / (2 + 0 + 5 + 1 + 2 + 3 + 2 + 3 + 9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205123229) 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 7 ways as a sum of consecutive naturals, for example, 3798552 + ... + 3798605.

It is an arithmetic number, because the mean of its divisors is an integer number (37985790).

Almost surely, 2^205123239 is an apocalyptic number.

205123239 is a deficient number, since it is larger than the sum of its proper divisors (98763081).

205123239 is an equidigital number, since it uses as much as digits as its factorization.

205123239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7597166 (or 7597160 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

The square root of 205123239 is about 14322.1241092235. The cubic root of 205123239 is about 589.7549868419.

The spelling of 205123239 in words is "two hundred five million, one hundred twenty-three thousand, two hundred thirty-nine".