20211121222121 has 8 divisors (see below), whose sum is σ = 20298226651560. Its totient is φ = 20124018890752.

The previous prime is 20211121222093. The next prime is 20211121222133. The reversal of 20211121222121 is 12122212111202.

It can be written as a sum of positive squares in 4 ways, for example, as 6244001440000 + 13967119782121 = 2498800^2 + 3737261^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 20211121222121 - 2²² = 20211117027817 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20211121222093 and 20211121222102.

It is not an unprimeable number, because it can be changed into a prime (20211121222021) 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, 12813665 + ... + 14304273.

It is an arithmetic number, because the mean of its divisors is an integer number (2537278331445).

Almost surely, 2^{20211121222121} is an apocalyptic number.

It is an amenable number.

20211121222121 is a deficient number, since it is larger than the sum of its proper divisors (87105429439).

20211121222121 is a wasteful number, since it uses less digits than its factorization.

20211121222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1549035.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 20211121222121 its reverse (12122212111202), we get a palindrome (32333333333323).

The spelling of 20211121222121 in words is "twenty trillion, two hundred eleven billion, one hundred twenty-one million, two hundred twenty-two thousand, one hundred twenty-one".