1211221010121 has 8 divisors (see below), whose sum is σ = 1709959073184. Its totient is φ = 759981810240.

The previous prime is 1211221010107. The next prime is 1211221010203. The reversal of 1211221010121 is 1210101221121.

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 1211221010121 - 2⁷ = 1211221009993 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1211221010121.

It is not an unprimeable number, because it can be changed into a prime (1211221010101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11874715735 + ... + 11874715836.

It is an arithmetic number, because the mean of its divisors is an integer number (213744884148).

Almost surely, 2^{1211221010121} is an apocalyptic number.

It is an amenable number.

1211221010121 is a deficient number, since it is larger than the sum of its proper divisors (498738063063).

1211221010121 is a wasteful number, since it uses less digits than its factorization.

1211221010121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23749431591.

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

Adding to 1211221010121 its reverse (1210101221121), we get a palindrome (2421322231242).

The spelling of 1211221010121 in words is "one trillion, two hundred eleven billion, two hundred twenty-one million, ten thousand, one hundred twenty-one".