21171417 has 4 divisors (see below), whose sum is σ = 28228560. Its totient is φ = 14114276.

The previous prime is 21171407. The next prime is 21171461. The reversal of 21171417 is 71417112.

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 21171417 - 2⁴ = 21171401 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21171407) 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, 3528567 + ... + 3528572.

It is an arithmetic number, because the mean of its divisors is an integer number (7057140).

Almost surely, 2^21171417 is an apocalyptic number.

It is an amenable number.

21171417 is a deficient number, since it is larger than the sum of its proper divisors (7057143).

21171417 is an equidigital number, since it uses as much as digits as its factorization.

21171417 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7057142.

The product of its digits is 392, while the sum is 24.

The square root of 21171417 is about 4601.2408109118. The cubic root of 21171417 is about 276.6410613228.

Adding to 21171417 its reverse (71417112), we get a palindrome (92588529).

The spelling of 21171417 in words is "twenty-one million, one hundred seventy-one thousand, four hundred seventeen".