21533219 has 2 divisors, whose sum is σ = 21533220. Its totient is φ = 21533218.

The previous prime is 21533207. The next prime is 21533227. The reversal of 21533219 is 91233512.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21533219 is a prime.

It is a super-2 number, since 2×21533219² = 927359041003922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21533269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10766609 + 10766610.

It is an arithmetic number, because the mean of its divisors is an integer number (10766610).

Almost surely, 2^21533219 is an apocalyptic number.

21533219 is a deficient number, since it is larger than the sum of its proper divisors (1).

21533219 is an equidigital number, since it uses as much as digits as its factorization.

21533219 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1620, while the sum is 26.

The square root of 21533219 is about 4640.3899620614. The cubic root of 21533219 is about 278.2080245170.

The spelling of 21533219 in words is "twenty-one million, five hundred thirty-three thousand, two hundred nineteen".