21344251 has 8 divisors (see below), whose sum is σ = 22100544. Its totient is φ = 20600640.

The previous prime is 21344249. The next prime is 21344273. The reversal of 21344251 is 15244312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21344251 - 2¹ = 21344249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21344051) 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 7 ways as a sum of consecutive naturals, for example, 321 + ... + 6541.

It is an arithmetic number, because the mean of its divisors is an integer number (2762568).

Almost surely, 2^21344251 is an apocalyptic number.

21344251 is a deficient number, since it is larger than the sum of its proper divisors (756293).

21344251 is an equidigital number, since it uses as much as digits as its factorization.

21344251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6341.

The product of its digits is 960, while the sum is 22.

The square root of 21344251 is about 4619.9838744307. The cubic root of 21344251 is about 277.3918134672.

Adding to 21344251 its reverse (15244312), we get a palindrome (36588563).

The spelling of 21344251 in words is "twenty-one million, three hundred forty-four thousand, two hundred fifty-one".