21717193 has 4 divisors (see below), whose sum is σ = 22222288. Its totient is φ = 21212100.

The previous prime is 21717191. The next prime is 21717203. The reversal of 21717193 is 39171712.

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 21717193 - 2¹ = 21717191 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21717191) 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, 252483 + ... + 252568.

It is an arithmetic number, because the mean of its divisors is an integer number (5555572).

Almost surely, 2^21717193 is an apocalyptic number.

It is an amenable number.

21717193 is a deficient number, since it is larger than the sum of its proper divisors (505095).

21717193 is an equidigital number, since it uses as much as digits as its factorization.

21717193 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 505094.

The product of its digits is 2646, while the sum is 31.

The square root of 21717193 is about 4660.1709196123. The cubic root of 21717193 is about 278.9980901108.

The spelling of 21717193 in words is "twenty-one million, seven hundred seventeen thousand, one hundred ninety-three".