21197417 has 4 divisors (see below), whose sum is σ = 21207120. Its totient is φ = 21187716.

The previous prime is 21197389. The next prime is 21197431. The reversal of 21197417 is 71479112.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21197417 - 2⁶ = 21197353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21197437) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 134 + ... + 6512.

It is an arithmetic number, because the mean of its divisors is an integer number (5301780).

Almost surely, 2^21197417 is an apocalyptic number.

It is an amenable number.

21197417 is a deficient number, since it is larger than the sum of its proper divisors (9703).

21197417 is an equidigital number, since it uses as much as digits as its factorization.

21197417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9702.

The product of its digits is 3528, while the sum is 32.

The square root of 21197417 is about 4604.0652688684. The cubic root of 21197417 is about 276.7542599376.

The spelling of 21197417 in words is "twenty-one million, one hundred ninety-seven thousand, four hundred seventeen".