21243141 has 10 divisors (see below), whose sum is σ = 31733702. Its totient is φ = 14162040.

The previous prime is 21243139. The next prime is 21243151. The reversal of 21243141 is 14134212.

It can be written as a sum of positive squares in only one way, i.e., 19766916 + 1476225 = 4446^2 + 1215^2 .

It is not a de Polignac number, because 21243141 - 2¹ = 21243139 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21243151) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 131050 + ... + 131211.

Almost surely, 2^21243141 is an apocalyptic number.

It is an amenable number.

21243141 is a deficient number, since it is larger than the sum of its proper divisors (10490561).

21243141 is an equidigital number, since it uses as much as digits as its factorization.

21243141 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262273 (or 262264 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 21243141 is about 4609.0282055982. The cubic root of 21243141 is about 276.9531084418.

Adding to 21243141 its reverse (14134212), we get a palindrome (35377353).

The spelling of 21243141 in words is "twenty-one million, two hundred forty-three thousand, one hundred forty-one".