21265219 has 2 divisors, whose sum is σ = 21265220. Its totient is φ = 21265218.

The previous prime is 21265217. The next prime is 21265241. The reversal of 21265219 is 91256212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21265219 - 2¹ = 21265217 is a prime.

It is a super-2 number, since 2×21265219² = 904419078235922, which contains 22 as substring.

Together with 21265217, 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 (21265217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10632609 + 10632610.

It is an arithmetic number, because the mean of its divisors is an integer number (10632610).

Almost surely, 2^21265219 is an apocalyptic number.

21265219 is a deficient number, since it is larger than the sum of its proper divisors (1).

21265219 is an equidigital number, since it uses as much as digits as its factorization.

21265219 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2160, while the sum is 28.

The square root of 21265219 is about 4611.4226655122. The cubic root of 21265219 is about 277.0490210261.

The spelling of 21265219 in words is "twenty-one million, two hundred sixty-five thousand, two hundred nineteen".