21333123 has 24 divisors (see below), whose sum is σ = 35363328. Its totient is φ = 12139632.

The previous prime is 21333107. The next prime is 21333133. The reversal of 21333123 is 32133312.

It is not a de Polignac number, because 21333123 - 2⁴ = 21333107 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21333096 and 21333105.

It is not an unprimeable number, because it can be changed into a prime (21333133) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18790 + ... + 19892.

It is an arithmetic number, because the mean of its divisors is an integer number (1473472).

Almost surely, 2^21333123 is an apocalyptic number.

21333123 is a deficient number, since it is larger than the sum of its proper divisors (14030205).

21333123 is a wasteful number, since it uses less digits than its factorization.

21333123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1423 (or 1420 counting only the distinct ones).

The product of its digits is 324, while the sum is 18.

The square root of 21333123 is about 4618.7793842096. The cubic root of 21333123 is about 277.3435982561.

Adding to 21333123 its reverse (32133312), we get a palindrome (53466435).

It can be divided in two parts, 2133312 and 3, that multiplied together give a palindrome (6399936).

The spelling of 21333123 in words is "twenty-one million, three hundred thirty-three thousand, one hundred twenty-three".