1211121120021 has 16 divisors (see below), whose sum is σ = 1623392016000. Its totient is φ = 803134398528.

The previous prime is 1211121119983. The next prime is 1211121120029. The reversal of 1211121120021 is 1200211211121.

It is a happy number.

It is not a de Polignac number, because 1211121120021 - 2⁷ = 1211121119893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211121120029) 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, 1892395 + ... + 2450183.

It is an arithmetic number, because the mean of its divisors is an integer number (101462001000).

Almost surely, 2^{1211121120021} is an apocalyptic number.

It is an amenable number.

1211121120021 is a deficient number, since it is larger than the sum of its proper divisors (412270895979).

1211121120021 is a wasteful number, since it uses less digits than its factorization.

1211121120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 561628.

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

Adding to 1211121120021 its reverse (1200211211121), we get a palindrome (2411332331142).

It can be divided in two parts, 1211121 and 120021, that multiplied together give a palindrome (145359953541).

The spelling of 1211121120021 in words is "one trillion, two hundred eleven billion, one hundred twenty-one million, one hundred twenty thousand, twenty-one".