20211211011121 has 4 divisors (see below), whose sum is σ = 21765919550452. Its totient is φ = 18656502471792.

The previous prime is 20211211011097. The next prime is 20211211011143. The reversal of 20211211011121 is 12111011211202.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9786636289600 + 10424574721521 = 3128360^2 + 3228711^2 .

It is a cyclic number.

It is not a de Polignac number, because 20211211011121 - 2²⁷ = 20211076793393 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20211211011095 and 20211211011104.

It is not an unprimeable number, because it can be changed into a prime (20211211011181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 777354269646 + ... + 777354269671.

It is an arithmetic number, because the mean of its divisors is an integer number (5441479887613).

Almost surely, 2^{20211211011121} is an apocalyptic number.

It is an amenable number.

20211211011121 is a deficient number, since it is larger than the sum of its proper divisors (1554708539331).

20211211011121 is a wasteful number, since it uses less digits than its factorization.

20211211011121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1554708539330.

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

Adding to 20211211011121 its reverse (12111011211202), we get a palindrome (32322222222323).

The spelling of 20211211011121 in words is "twenty trillion, two hundred eleven billion, two hundred eleven million, eleven thousand, one hundred twenty-one".