21344231 has 16 divisors (see below), whose sum is σ = 23442048. Its totient is φ = 19353600.

The previous prime is 21344209. The next prime is 21344237. The reversal of 21344231 is 13244312.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21344231 is a prime.

It is a super-2 number, since 2×21344231² = 911152393962722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21344237) 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, 78626 + ... + 78896.

It is an arithmetic number, because the mean of its divisors is an integer number (1465128).

Almost surely, 2^21344231 is an apocalyptic number.

21344231 is a deficient number, since it is larger than the sum of its proper divisors (2097817).

21344231 is a wasteful number, since it uses less digits than its factorization.

21344231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442.

The product of its digits is 576, while the sum is 20.

The square root of 21344231 is about 4619.9817099205. The cubic root of 21344231 is about 277.3917268265.

Adding to 21344231 its reverse (13244312), we get a palindrome (34588543).

It can be divided in two parts, 213 and 44231, that added together give a palindrome (44444).

The spelling of 21344231 in words is "twenty-one million, three hundred forty-four thousand, two hundred thirty-one".