21213417 has 8 divisors (see below), whose sum is σ = 28602720. Its totient is φ = 13983200.

The previous prime is 21213407. The next prime is 21213419. The reversal of 21213417 is 71431212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21213417 - 2¹¹ = 21211369 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21213393 and 21213402.

It is not an unprimeable number, because it can be changed into a prime (21213419) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39459 + ... + 39992.

It is an arithmetic number, because the mean of its divisors is an integer number (3575340).

Almost surely, 2^21213417 is an apocalyptic number.

It is an amenable number.

21213417 is a deficient number, since it is larger than the sum of its proper divisors (7389303).

21213417 is an equidigital number, since it uses as much as digits as its factorization.

21213417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79543.

The product of its digits is 336, while the sum is 21.

The square root of 21213417 is about 4605.8025359323. The cubic root of 21213417 is about 276.8238746225.

Adding to 21213417 its reverse (71431212), we get a palindrome (92644629).

The spelling of 21213417 in words is "twenty-one million, two hundred thirteen thousand, four hundred seventeen".