21123023211 has 16 divisors (see below), whose sum is σ = 31324118400. Its totient is φ = 14068177704.

The previous prime is 21123023191. The next prime is 21123023213. The reversal of 21123023211 is 11232032112.

It is not a de Polignac number, because 21123023211 - 2⁵ = 21123023179 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21123023213) 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, 356361 + ... + 411386.

It is an arithmetic number, because the mean of its divisors is an integer number (1957757400).

Almost surely, 2^21123023211 is an apocalyptic number.

21123023211 is a deficient number, since it is larger than the sum of its proper divisors (10201095189).

21123023211 is a wasteful number, since it uses less digits than its factorization.

21123023211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 768775 (or 768769 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21123023211 its reverse (11232032112), we get a palindrome (32355055323).

The spelling of 21123023211 in words is "twenty-one billion, one hundred twenty-three million, twenty-three thousand, two hundred eleven".