21224403123 has 16 divisors (see below), whose sum is σ = 35282125056. Its totient is φ = 11025663840.

The previous prime is 21224403119. The next prime is 21224403127. The reversal of 21224403123 is 32130442212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21224403119) and next prime (21224403127).

It is not a de Polignac number, because 21224403123 - 2² = 21224403119 is a prime.

It is a super-2 number, since 2×21224403123² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21224403093 and 21224403102.

It is not an unprimeable number, because it can be changed into a prime (21224403127) 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, 45940036 + ... + 45940497.

It is an arithmetic number, because the mean of its divisors is an integer number (2205132816).

Almost surely, 2^21224403123 is an apocalyptic number.

21224403123 is a deficient number, since it is larger than the sum of its proper divisors (14057721933).

21224403123 is a wasteful number, since it uses less digits than its factorization.

21224403123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91880554.

The product of its (nonzero) digits is 2304, while the sum is 24.

Adding to 21224403123 its reverse (32130442212), we get a palindrome (53354845335).

The spelling of 21224403123 in words is "twenty-one billion, two hundred twenty-four million, four hundred three thousand, one hundred twenty-three".