21144271 has 4 divisors (see below), whose sum is σ = 21412000. Its totient is φ = 20876544.

The previous prime is 21144269. The next prime is 21144287. The reversal of 21144271 is 17244112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21144271 - 2¹ = 21144269 is a prime.

It is a super-2 number, since 2×21144271² = 894160392242882, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21141271) 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, 133746 + ... + 133903.

It is an arithmetic number, because the mean of its divisors is an integer number (5353000).

Almost surely, 2^21144271 is an apocalyptic number.

21144271 is a deficient number, since it is larger than the sum of its proper divisors (267729).

21144271 is an equidigital number, since it uses as much as digits as its factorization.

21144271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 267728.

The product of its digits is 448, while the sum is 22.

The square root of 21144271 is about 4598.2900082531. The cubic root of 21144271 is about 276.5227743232.

Adding to 21144271 its reverse (17244112), we get a palindrome (38388383).

The spelling of 21144271 in words is "twenty-one million, one hundred forty-four thousand, two hundred seventy-one".