21121111223 has 8 divisors (see below), whose sum is σ = 21204690192. Its totient is φ = 21037585536.

The previous prime is 21121111153. The next prime is 21121111279. The reversal of 21121111223 is 32211112112.

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 21121111223 - 2³² = 16826143927 is a prime.

It is a super-2 number, since 2×21121111223² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121110223) 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, 904511 + ... + 927567.

It is an arithmetic number, because the mean of its divisors is an integer number (2650586274).

Almost surely, 2^21121111223 is an apocalyptic number.

21121111223 is a deficient number, since it is larger than the sum of its proper divisors (83578969).

21121111223 is a wasteful number, since it uses less digits than its factorization.

21121111223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26641.

The product of its digits is 48, while the sum is 17.

Adding to 21121111223 its reverse (32211112112), we get a palindrome (53332223335).

The spelling of 21121111223 in words is "twenty-one billion, one hundred twenty-one million, one hundred eleven thousand, two hundred twenty-three".