205623139 has 2 divisors, whose sum is σ = 205623140. Its totient is φ = 205623138.

The previous prime is 205623133. The next prime is 205623161. The reversal of 205623139 is 931326502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 205623139 - 2⁵ = 205623107 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 205623139.

It is not a weakly prime, because it can be changed into another prime (205623133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102811569 + 102811570.

It is an arithmetic number, because the mean of its divisors is an integer number (102811570).

Almost surely, 2^205623139 is an apocalyptic number.

205623139 is a deficient number, since it is larger than the sum of its proper divisors (1).

205623139 is an equidigital number, since it uses as much as digits as its factorization.

205623139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9720, while the sum is 31.

The square root of 205623139 is about 14339.5655094567. The cubic root of 205623139 is about 590.2336898648.

The spelling of 205623139 in words is "two hundred five million, six hundred twenty-three thousand, one hundred thirty-nine".