21232123 has 16 divisors (see below), whose sum is σ = 23773536. Its totient is φ = 18800640.

The previous prime is 21232121. The next prime is 21232157. The reversal of 21232123 is 32123212.

21232123 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It is a cyclic number.

It is not a de Polignac number, because 21232123 - 2¹ = 21232121 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21232097 and 21232106.

It is not an unprimeable number, because it can be changed into a prime (21232121) 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 15 ways as a sum of consecutive naturals, for example, 109915 + ... + 110107.

It is an arithmetic number, because the mean of its divisors is an integer number (1485846).

Almost surely, 2^21232123 is an apocalyptic number.

21232123 is a deficient number, since it is larger than the sum of its proper divisors (2541413).

21232123 is a wasteful number, since it uses less digits than its factorization.

21232123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 414.

The product of its digits is 144, while the sum is 16.

The square root of 21232123 is about 4607.8327877648. The cubic root of 21232123 is about 276.9052185203.

Adding to 21232123 its reverse (32123212), we get a palindrome (53355335).

It can be divided in two parts, 2123212 and 3, that multiplied together give a palindrome (6369636).

The spelling of 21232123 in words is "twenty-one million, two hundred thirty-two thousand, one hundred twenty-three".