21442017 has 4 divisors (see below), whose sum is σ = 28589360. Its totient is φ = 14294676.

The previous prime is 21442009. The next prime is 21442019. The reversal of 21442017 is 71024412.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21442017 - 2³ = 21442009 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21441984 and 21442002.

It is not an unprimeable number, because it can be changed into a prime (21442019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3573667 + ... + 3573672.

It is an arithmetic number, because the mean of its divisors is an integer number (7147340).

Almost surely, 2^21442017 is an apocalyptic number.

It is an amenable number.

21442017 is a deficient number, since it is larger than the sum of its proper divisors (7147343).

21442017 is an equidigital number, since it uses as much as digits as its factorization.

21442017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7147342.

The product of its (nonzero) digits is 448, while the sum is 21.

The square root of 21442017 is about 4630.5525588206. The cubic root of 21442017 is about 277.8146937189.

Adding to 21442017 its reverse (71024412), we get a palindrome (92466429).

The spelling of 21442017 in words is "twenty-one million, four hundred forty-two thousand, seventeen".