205099987 has 2 divisors, whose sum is σ = 205099988. Its totient is φ = 205099986.

The previous prime is 205099967. The next prime is 205100009. The reversal of 205099987 is 789990502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 205099987 - 2¹¹ = 205097939 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 205099987.

It is not a weakly prime, because it can be changed into another prime (205099907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102549993 + 102549994.

It is an arithmetic number, because the mean of its divisors is an integer number (102549994).

Almost surely, 2^205099987 is an apocalyptic number.

205099987 is a deficient number, since it is larger than the sum of its proper divisors (1).

205099987 is an equidigital number, since it uses as much as digits as its factorization.

205099987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 408240, while the sum is 49.

The square root of 205099987 is about 14321.3123351179. The cubic root of 205099987 is about 589.7327018631.

The spelling of 205099987 in words is "two hundred five million, ninety-nine thousand, nine hundred eighty-seven".