21022323123 has 4 divisors (see below), whose sum is σ = 28029764168. Its totient is φ = 14014882080.

The previous prime is 21022323103. The next prime is 21022323151. The reversal of 21022323123 is 32132322012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21022323123 - 2¹⁰ = 21022322099 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21022323123.

It is not an unprimeable number, because it can be changed into a prime (21022323103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3503720518 + ... + 3503720523.

It is an arithmetic number, because the mean of its divisors is an integer number (7007441042).

Almost surely, 2^21022323123 is an apocalyptic number.

21022323123 is a deficient number, since it is larger than the sum of its proper divisors (7007441045).

21022323123 is an equidigital number, since it uses as much as digits as its factorization.

21022323123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7007441044.

The product of its (nonzero) digits is 864, while the sum is 21.

Adding to 21022323123 its reverse (32132322012), we get a palindrome (53154645135).

The spelling of 21022323123 in words is "twenty-one billion, twenty-two million, three hundred twenty-three thousand, one hundred twenty-three".