205186905019 has 4 divisors (see below), whose sum is σ = 210191463720. Its totient is φ = 200182346320.

The previous prime is 205186905017. The next prime is 205186905023. The reversal of 205186905019 is 910509681502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 205186905019 - 2¹ = 205186905017 is a prime.

It is a super-2 number, since 2×205186905019² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 205186905019.

It is not an unprimeable number, because it can be changed into a prime (205186905013) 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, 2502279289 + ... + 2502279370.

It is an arithmetic number, because the mean of its divisors is an integer number (52547865930).

Almost surely, 2^205186905019 is an apocalyptic number.

205186905019 is a deficient number, since it is larger than the sum of its proper divisors (5004558701).

205186905019 is an equidigital number, since it uses as much as digits as its factorization.

205186905019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5004558700.

The product of its (nonzero) digits is 194400, while the sum is 46.

The spelling of 205186905019 in words is "two hundred five billion, one hundred eighty-six million, nine hundred five thousand, nineteen".