1221212203211 has 16 divisors (see below), whose sum is σ = 1639669532928. Its totient is φ = 878394391200.

The previous prime is 1221212203187. The next prime is 1221212203307. The reversal of 1221212203211 is 1123022121221.

It is a cyclic number.

It is not a de Polignac number, because 1221212203211 - 2¹⁸ = 1221211941067 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221212203111) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 609995105 + ... + 609997106.

It is an arithmetic number, because the mean of its divisors is an integer number (102479345808).

Almost surely, 2^{1221212203211} is an apocalyptic number.

1221212203211 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1221212203211 is a deficient number, since it is larger than the sum of its proper divisors (418457329717).

1221212203211 is a wasteful number, since it uses less digits than its factorization.

1221212203211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1219992242.

The product of its (nonzero) digits is 192, while the sum is 20.

Adding to 1221212203211 its reverse (1123022121221), we get a palindrome (2344234324432).

The spelling of 1221212203211 in words is "one trillion, two hundred twenty-one billion, two hundred twelve million, two hundred three thousand, two hundred eleven".