21130023123 has 40 divisors (see below), whose sum is σ = 35621538480. Its totient is φ = 12364470720.

The previous prime is 21130023091. The next prime is 21130023127. The reversal of 21130023123 is 32132003112.

It is not a de Polignac number, because 21130023123 - 2⁵ = 21130023091 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21130023096 and 21130023105.

It is not an unprimeable number, because it can be changed into a prime (21130023127) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 383040 + ... + 434717.

It is an arithmetic number, because the mean of its divisors is an integer number (890538462).

Almost surely, 2^21130023123 is an apocalyptic number.

21130023123 is a deficient number, since it is larger than the sum of its proper divisors (14491515357).

21130023123 is a wasteful number, since it uses less digits than its factorization.

21130023123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 817809 (or 817800 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21130023123 its reverse (32132003112), we get a palindrome (53262026235).

The spelling of 21130023123 in words is "twenty-one billion, one hundred thirty million, twenty-three thousand, one hundred twenty-three".