21211202122121 has 8 divisors (see below), whose sum is σ = 24357361288800. Its totient is φ = 18268020966240.

The previous prime is 21211202122091. The next prime is 21211202122177. The reversal of 21211202122121 is 12122120211212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21211202122121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21211202122093 and 21211202122102.

It is not an unprimeable number, because it can be changed into a prime (21211202122021) 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, 50744502476 + ... + 50744502893.

It is an arithmetic number, because the mean of its divisors is an integer number (3044670161100).

Almost surely, 2^{21211202122121} is an apocalyptic number.

It is an amenable number.

21211202122121 is a deficient number, since it is larger than the sum of its proper divisors (3146159166679).

21211202122121 is a wasteful number, since it uses less digits than its factorization.

21211202122121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101489005399.

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

Adding to 21211202122121 its reverse (12122120211212), we get a palindrome (33333322333333).

The spelling of 21211202122121 in words is "twenty-one trillion, two hundred eleven billion, two hundred two million, one hundred twenty-two thousand, one hundred twenty-one".