21211022122121 has 8 divisors (see below), whose sum is σ = 23068803954504. Its totient is φ = 19385549539200.

The previous prime is 21211022122109. The next prime is 21211022122153. The reversal of 21211022122121 is 12122122011212.

It can be written as a sum of positive squares in 4 ways, for example, as 213906250000 + 20997115872121 = 462500^2 + 4582261^2 .

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

It is not a de Polignac number, because 21211022122121 - 2¹⁴ = 21211022105737 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21211022122093 and 21211022122102.

It is not an unprimeable number, because it can be changed into a prime (21211022122721) 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, 8077310996 + ... + 8077313621.

It is an arithmetic number, because the mean of its divisors is an integer number (2883600494313).

Almost surely, 2^{21211022122121} is an apocalyptic number.

It is an amenable number.

21211022122121 is a deficient number, since it is larger than the sum of its proper divisors (1857781832383).

21211022122121 is a wasteful number, since it uses less digits than its factorization.

21211022122121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16154624731.

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

Adding to 21211022122121 its reverse (12122122011212), we get a palindrome (33333144133333).

The spelling of 21211022122121 in words is "twenty-one trillion, two hundred eleven billion, twenty-two million, one hundred twenty-two thousand, one hundred twenty-one".