21332121 has 4 divisors (see below), whose sum is σ = 28442832. Its totient is φ = 14221412.

The previous prime is 21332119. The next prime is 21332141. The reversal of 21332121 is 12123312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21332121 - 2¹ = 21332119 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21332121.

It is not an unprimeable number, because it can be changed into a prime (21332141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3555351 + ... + 3555356.

It is an arithmetic number, because the mean of its divisors is an integer number (7110708).

Almost surely, 2^21332121 is an apocalyptic number.

It is an amenable number.

21332121 is a deficient number, since it is larger than the sum of its proper divisors (7110711).

21332121 is an equidigital number, since it uses as much as digits as its factorization.

21332121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7110710.

The product of its digits is 72, while the sum is 15.

The square root of 21332121 is about 4618.6709127194. The cubic root of 21332121 is about 277.3392559846.

Adding to 21332121 its reverse (12123312), we get a palindrome (33455433).

The spelling of 21332121 in words is "twenty-one million, three hundred thirty-two thousand, one hundred twenty-one".