21442171 has 8 divisors (see below), whose sum is σ = 21878064. Its totient is φ = 21009120.

The previous prime is 21442163. The next prime is 21442229. The reversal of 21442171 is 17124412.

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 21442171 - 2³ = 21442163 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (21442471) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20661 + ... + 21673.

It is an arithmetic number, because the mean of its divisors is an integer number (2734758).

Almost surely, 2^21442171 is an apocalyptic number.

21442171 is a deficient number, since it is larger than the sum of its proper divisors (435893).

21442171 is a wasteful number, since it uses less digits than its factorization.

21442171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1421.

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

The square root of 21442171 is about 4630.5691874758. The cubic root of 21442171 is about 277.8153588206.

Adding to 21442171 its reverse (17124412), we get a palindrome (38566583).

The spelling of 21442171 in words is "twenty-one million, four hundred forty-two thousand, one hundred seventy-one".