21130323123 has 32 divisors (see below), whose sum is σ = 36183038976. Its totient is φ = 10661067648.

The previous prime is 21130323091. The next prime is 21130323131. The reversal of 21130323123 is 32132303112.

It is not a de Polignac number, because 21130323123 - 2⁵ = 21130323091 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 21130323123.

It is not an unprimeable number, because it can be changed into a prime (21130323143) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1676340 + ... + 1688897.

It is an arithmetic number, because the mean of its divisors is an integer number (1130719968).

Almost surely, 2^21130323123 is an apocalyptic number.

21130323123 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21130323123 is a deficient number, since it is larger than the sum of its proper divisors (15052715853).

21130323123 is a wasteful number, since it uses less digits than its factorization.

21130323123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3365283.

The product of its (nonzero) digits is 648, while the sum is 21.

Adding to 21130323123 its reverse (32132303112), we get a palindrome (53262626235).

The spelling of 21130323123 in words is "twenty-one billion, one hundred thirty million, three hundred twenty-three thousand, one hundred twenty-three".