21220221121 has 8 divisors (see below), whose sum is σ = 23159543904. Its totient is φ = 19282600320.

The previous prime is 21220221119. The next prime is 21220221179. The reversal of 21220221121 is 12112202212.

It is a happy number.

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 21220221121 - 2¹ = 21220221119 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21220221095 and 21220221104.

It is not an unprimeable number, because it can be changed into a prime (21220221221) 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, 399351 + ... + 449356.

It is an arithmetic number, because the mean of its divisors is an integer number (2894942988).

Almost surely, 2^21220221121 is an apocalyptic number.

It is an amenable number.

21220221121 is a deficient number, since it is larger than the sum of its proper divisors (1939322783).

21220221121 is a wasteful number, since it uses less digits than its factorization.

21220221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 850991.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21220221121 its reverse (12112202212), we get a palindrome (33332423333).

The spelling of 21220221121 in words is "twenty-one billion, two hundred twenty million, two hundred twenty-one thousand, one hundred twenty-one".