205006639 has 2 divisors, whose sum is σ = 205006640. Its totient is φ = 205006638.

The previous prime is 205006631. The next prime is 205006657. The reversal of 205006639 is 936600502.

205006639 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 205006639 - 2³ = 205006631 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 205006639.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205006631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102503319 + 102503320.

It is an arithmetic number, because the mean of its divisors is an integer number (102503320).

Almost surely, 2^205006639 is an apocalyptic number.

205006639 is a deficient number, since it is larger than the sum of its proper divisors (1).

205006639 is an equidigital number, since it uses as much as digits as its factorization.

205006639 is an evil number, because the sum of its binary digits is even.

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

The square root of 205006639 is about 14318.0529053360. The cubic root of 205006639 is about 589.6432191301.

The spelling of 205006639 in words is "two hundred five million, six thousand, six hundred thirty-nine".