21124220223 has 16 divisors (see below), whose sum is σ = 29571742080. Its totient is φ = 13394252256.

The previous prime is 21124220177. The next prime is 21124220263. The reversal of 21124220223 is 32202242112.

It is not a de Polignac number, because 21124220223 - 2⁸ = 21124219967 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21124220223.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21124220263) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1806165 + ... + 1817822.

It is an arithmetic number, because the mean of its divisors is an integer number (1848233880).

Almost surely, 2^21124220223 is an apocalyptic number.

21124220223 is a deficient number, since it is larger than the sum of its proper divisors (8447521857).

21124220223 is a wasteful number, since it uses less digits than its factorization.

21124220223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3624086.

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21124220223 its reverse (32202242112), we get a palindrome (53326462335).

The spelling of 21124220223 in words is "twenty-one billion, one hundred twenty-four million, two hundred twenty thousand, two hundred twenty-three".