1212211220209 has 4 divisors (see below), whose sum is σ = 1322412240240. Its totient is φ = 1102010200180.

The previous prime is 1212211220197. The next prime is 1212211220251. The reversal of 1212211220209 is 9020221122121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1212211220209 - 2¹⁹ = 1212210695921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1212281220209) 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 in 3 ways as a sum of consecutive naturals, for example, 55100509999 + ... + 55100510020.

It is an arithmetic number, because the mean of its divisors is an integer number (330603060060).

Almost surely, 2^{1212211220209} is an apocalyptic number.

It is an amenable number.

1212211220209 is a deficient number, since it is larger than the sum of its proper divisors (110201020031).

1212211220209 is a wasteful number, since it uses less digits than its factorization.

1212211220209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110201020030.

The product of its (nonzero) digits is 576, while the sum is 25.

The spelling of 1212211220209 in words is "one trillion, two hundred twelve billion, two hundred eleven million, two hundred twenty thousand, two hundred nine".