1211200121121 has 16 divisors (see below), whose sum is σ = 1659798868224. Its totient is φ = 785252916864.

The previous prime is 1211200121071. The next prime is 1211200121123. The reversal of 1211200121121 is 1211210021121.

It is a happy number.

It is not a de Polignac number, because 1211200121121 - 2³⁷ = 1073761167649 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1211200121121.

It is not an unprimeable number, because it can be changed into a prime (1211200121123) 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, 27334780 + ... + 27379053.

It is an arithmetic number, because the mean of its divisors is an integer number (103737429264).

Almost surely, 2^{1211200121121} is an apocalyptic number.

It is an amenable number.

1211200121121 is a deficient number, since it is larger than the sum of its proper divisors (448598747103).

1211200121121 is a wasteful number, since it uses less digits than its factorization.

1211200121121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54714040.

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

Adding to 1211200121121 its reverse (1211210021121), we get a palindrome (2422410142242).

The spelling of 1211200121121 in words is "one trillion, two hundred eleven billion, two hundred million, one hundred twenty-one thousand, one hundred twenty-one".