21123000223 has 12 divisors (see below), whose sum is σ = 22911002688. Its totient is φ = 19465617600.

The previous prime is 21123000187. The next prime is 21123000229. The reversal of 21123000223 is 32200032112.

It is not a de Polignac number, because 21123000223 - 2²⁵ = 21089445791 is a prime.

It is a super-2 number, since 2×21123000223² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21123000197 and 21123000206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21123000229) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2415 + ... + 205552.

It is an arithmetic number, because the mean of its divisors is an integer number (1909250224).

Almost surely, 2^21123000223 is an apocalyptic number.

21123000223 is a deficient number, since it is larger than the sum of its proper divisors (1788002465).

21123000223 is a wasteful number, since it uses less digits than its factorization.

21123000223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208594 (or 208581 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

Adding to 21123000223 its reverse (32200032112), we get a palindrome (53323032335).

The spelling of 21123000223 in words is "twenty-one billion, one hundred twenty-three million, two hundred twenty-three", and thus it is an aban number.