1212211011221 has 24 divisors (see below), whose sum is σ = 1440485876736. Its totient is φ = 1016676437280.

The previous prime is 1212211011169. The next prime is 1212211011229. The reversal of 1212211011221 is 1221101122121.

It is not a de Polignac number, because 1212211011221 - 2¹⁴ = 1212210994837 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1212211011221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212211011229) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9440711 + ... + 9568251.

It is an arithmetic number, because the mean of its divisors is an integer number (60020244864).

Almost surely, 2^{1212211011221} is an apocalyptic number.

It is an amenable number.

1212211011221 is a deficient number, since it is larger than the sum of its proper divisors (228274865515).

1212211011221 is a wasteful number, since it uses less digits than its factorization.

1212211011221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131729 (or 131722 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 1212211011221 its reverse (1221101122121), we get a palindrome (2433312133342).

The spelling of 1212211011221 in words is "one trillion, two hundred twelve billion, two hundred eleven million, eleven thousand, two hundred twenty-one".