205431139 has 4 divisors (see below), whose sum is σ = 205459920. Its totient is φ = 205402360.

The previous prime is 205431137. The next prime is 205431181. The reversal of 205431139 is 931134502.

205431139 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 205431139 - 2¹ = 205431137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205431137) 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, 5274 + ... + 20944.

It is an arithmetic number, because the mean of its divisors is an integer number (51364980).

Almost surely, 2^205431139 is an apocalyptic number.

205431139 is a deficient number, since it is larger than the sum of its proper divisors (28781).

205431139 is a wasteful number, since it uses less digits than its factorization.

205431139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28780.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 205431139 is about 14332.8691824073. The cubic root of 205431139 is about 590.0499229996.

The spelling of 205431139 in words is "two hundred five million, four hundred thirty-one thousand, one hundred thirty-nine".