1221211010121 has 8 divisors (see below), whose sum is σ = 1628384550624. Its totient is φ = 814089071520.

The previous prime is 1221211010119. The next prime is 1221211010137. The reversal of 1221211010121 is 1210101121221.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1221211010121 - 2¹ = 1221211010119 is a prime.

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 1221211010121.

It is not an unprimeable number, because it can be changed into a prime (1221211010111) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 12845220 + ... + 12939941.

It is an arithmetic number, because the mean of its divisors is an integer number (203548068828).

Almost surely, 2^{1221211010121} is an apocalyptic number.

It is an amenable number.

1221211010121 is a deficient number, since it is larger than the sum of its proper divisors (407173540503).

1221211010121 is a wasteful number, since it uses less digits than its factorization.

1221211010121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25800951.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1221211010121 its reverse (1210101121221), we get a palindrome (2431312131342).

The spelling of 1221211010121 in words is "one trillion, two hundred twenty-one billion, two hundred eleven million, ten thousand, one hundred twenty-one".