21245219 has 2 divisors, whose sum is σ = 21245220. Its totient is φ = 21245218.

The previous prime is 21245183. The next prime is 21245221. The reversal of 21245219 is 91254212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21245219 - 2¹² = 21241123 is a prime.

It is a super-2 number, since 2×21245219² = 902718660715922, which contains 22 as substring.

Together with 21245221, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21245519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10622609 + 10622610.

It is an arithmetic number, because the mean of its divisors is an integer number (10622610).

Almost surely, 2^21245219 is an apocalyptic number.

21245219 is a deficient number, since it is larger than the sum of its proper divisors (1).

21245219 is an equidigital number, since it uses as much as digits as its factorization.

21245219 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1440, while the sum is 26.

The square root of 21245219 is about 4609.2536272156. The cubic root of 21245219 is about 276.9621386474.

The spelling of 21245219 in words is "twenty-one million, two hundred forty-five thousand, two hundred nineteen".