205851263987 has 2 divisors, whose sum is σ = 205851263988. Its totient is φ = 205851263986.

The previous prime is 205851263941. The next prime is 205851263999. The reversal of 205851263987 is 789362158502.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 205851263987 - 2⁶ = 205851263923 is a prime.

It is not a weakly prime, because it can be changed into another prime (205851260987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102925631993 + 102925631994.

It is an arithmetic number, because the mean of its divisors is an integer number (102925631994).

Almost surely, 2^205851263987 is an apocalyptic number.

205851263987 is a deficient number, since it is larger than the sum of its proper divisors (1).

205851263987 is an equidigital number, since it uses as much as digits as its factorization.

205851263987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7257600, while the sum is 56.

The spelling of 205851263987 in words is "two hundred five billion, eight hundred fifty-one million, two hundred sixty-three thousand, nine hundred eighty-seven".