21221021221121 has 8 divisors (see below), whose sum is σ = 21227044507200. Its totient is φ = 21214998295600.

The previous prime is 21221021221111. The next prime is 21221021221151. The reversal of 21221021221121 is 12112212012212.

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 21221021221121 - 2²² = 21221017026817 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21221021221093 and 21221021221102.

It is not an unprimeable number, because it can be changed into a prime (21221021221111) 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, 154110020 + ... + 154247658.

It is an arithmetic number, because the mean of its divisors is an integer number (2653380563400).

Almost surely, 2^{21221021221121} is an apocalyptic number.

It is an amenable number.

21221021221121 is a deficient number, since it is larger than the sum of its proper divisors (6023286079).

21221021221121 is a wasteful number, since it uses less digits than its factorization.

21221021221121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180279.

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

Adding to 21221021221121 its reverse (12112212012212), we get a palindrome (33333233233333).

The spelling of 21221021221121 in words is "twenty-one trillion, two hundred twenty-one billion, twenty-one million, two hundred twenty-one thousand, one hundred twenty-one".