1216206205 has 16 divisors (see below), whose sum is σ = 1512529200. Its totient is φ = 937699840.

The previous prime is 1216206179. The next prime is 1216206217. The reversal of 1216206205 is 5026026121.

It can be written as a sum of positive squares in 8 ways, for example, as 5583769 + 1210622436 = 2363^2 + 34794^2 .

It is not a de Polignac number, because 1216206205 - 2⁷ = 1216206077 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1216206205.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 75135 + ... + 89875.

It is an arithmetic number, because the mean of its divisors is an integer number (94533075).

Almost surely, 2^1216206205 is an apocalyptic number.

It is an amenable number.

1216206205 is a deficient number, since it is larger than the sum of its proper divisors (296322995).

1216206205 is a wasteful number, since it uses less digits than its factorization.

1216206205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15344.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 1216206205 is about 34874.1480899534. The cubic root of 1216206205 is about 1067.4209891667.

The spelling of 1216206205 in words is "one billion, two hundred sixteen million, two hundred six thousand, two hundred five".