21044171 has 4 divisors (see below), whose sum is σ = 21170352. Its totient is φ = 20917992.

The previous prime is 21044129. The next prime is 21044197. The reversal of 21044171 is 17144012.

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 21044171 - 2²² = 16849867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21040171) 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, 62840 + ... + 63173.

It is an arithmetic number, because the mean of its divisors is an integer number (5292588).

Almost surely, 2^21044171 is an apocalyptic number.

21044171 is a deficient number, since it is larger than the sum of its proper divisors (126181).

21044171 is a wasteful number, since it uses less digits than its factorization.

21044171 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126180.

The product of its (nonzero) digits is 224, while the sum is 20.

The square root of 21044171 is about 4587.3926145470. The cubic root of 21044171 is about 276.0857177922.

Adding to 21044171 its reverse (17144012), we get a palindrome (38188183).

It can be divided in two parts, 210441 and 71, that multiplied together give a triangular number (14941311 = T₅₄₆₆).

The spelling of 21044171 in words is "twenty-one million, forty-four thousand, one hundred seventy-one".