21342417 has 4 divisors (see below), whose sum is σ = 28456560. Its totient is φ = 14228276.

The previous prime is 21342407. The next prime is 21342421. The reversal of 21342417 is 71424312.

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 a cyclic number.

It is not a de Polignac number, because 21342417 - 2⁸ = 21342161 is a prime.

It is a super-3 number, since 3×21342417³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21342407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3557067 + ... + 3557072.

It is an arithmetic number, because the mean of its divisors is an integer number (7114140).

Almost surely, 2^21342417 is an apocalyptic number.

It is an amenable number.

21342417 is a deficient number, since it is larger than the sum of its proper divisors (7114143).

21342417 is an equidigital number, since it uses as much as digits as its factorization.

21342417 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7114142.

The product of its digits is 1344, while the sum is 24.

The square root of 21342417 is about 4619.7853846256. The cubic root of 21342417 is about 277.3838682964.

Adding to 21342417 its reverse (71424312), we get a palindrome (92766729).

The spelling of 21342417 in words is "twenty-one million, three hundred forty-two thousand, four hundred seventeen".