21122021122121 has 32 divisors (see below), whose sum is σ = 23615987996160. Its totient is φ = 18800862566400.

The previous prime is 21122021122079. The next prime is 21122021122187. The reversal of 21122021122121 is 12122112022112.

It is a cyclic number.

It is not a de Polignac number, because 21122021122121 - 2¹⁴ = 21122021105737 is a prime.

It is a super-2 number, since 2×21122021122121² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21122021122093 and 21122021122102.

It is not an unprimeable number, because it can be changed into a prime (21122021122721) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5477690 + ... + 8499948.

It is an arithmetic number, because the mean of its divisors is an integer number (737999624880).

Almost surely, 2^{21122021122121} is an apocalyptic number.

It is an amenable number.

21122021122121 is a deficient number, since it is larger than the sum of its proper divisors (2493966874039).

21122021122121 is a wasteful number, since it uses less digits than its factorization.

21122021122121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3022625.

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

Adding to 21122021122121 its reverse (12122112022112), we get a palindrome (33244133144233).

It can be divided in two parts, 2112202 and 1122121, that added together give a palindrome (3234323).

The spelling of 21122021122121 in words is "twenty-one trillion, one hundred twenty-two billion, twenty-one million, one hundred twenty-two thousand, one hundred twenty-one".