21223021121 has 4 divisors (see below), whose sum is σ = 21224110512. Its totient is φ = 21221931732.

The previous prime is 21223021117. The next prime is 21223021151. The reversal of 21223021121 is 12112032212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21223021121 - 2² = 21223021117 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21223021121.

It is not an unprimeable number, because it can be changed into a prime (21223021151) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 514931 + ... + 554616.

It is an arithmetic number, because the mean of its divisors is an integer number (5306027628).

Almost surely, 2^21223021121 is an apocalyptic number.

It is an amenable number.

21223021121 is a deficient number, since it is larger than the sum of its proper divisors (1089391).

21223021121 is a wasteful number, since it uses less digits than its factorization.

21223021121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1089390.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21223021121 its reverse (12112032212), we get a palindrome (33335053333).

The spelling of 21223021121 in words is "twenty-one billion, two hundred twenty-three million, twenty-one thousand, one hundred twenty-one".