205612139 has 2 divisors, whose sum is σ = 205612140. Its totient is φ = 205612138.

The previous prime is 205612087. The next prime is 205612177. The reversal of 205612139 is 931216502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 205612139 - 2⁸ = 205611883 is a prime.

It is not a weakly prime, because it can be changed into another prime (205612189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102806069 + 102806070.

It is an arithmetic number, because the mean of its divisors is an integer number (102806070).

Almost surely, 2^205612139 is an apocalyptic number.

205612139 is a deficient number, since it is larger than the sum of its proper divisors (1).

205612139 is an equidigital number, since it uses as much as digits as its factorization.

205612139 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 205612139 is about 14339.1819501672. The cubic root of 205612139 is about 590.2231646448.

The spelling of 205612139 in words is "two hundred five million, six hundred twelve thousand, one hundred thirty-nine".