21220411 has 4 divisors (see below), whose sum is σ = 21738024. Its totient is φ = 20702800.

The previous prime is 21220393. The next prime is 21220417. The reversal of 21220411 is 11402212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21220411 - 2⁵ = 21220379 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21220391 and 21220400.

It is not an unprimeable number, because it can be changed into a prime (21220417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 258745 + ... + 258826.

It is an arithmetic number, because the mean of its divisors is an integer number (5434506).

Almost surely, 2^21220411 is an apocalyptic number.

21220411 is a deficient number, since it is larger than the sum of its proper divisors (517613).

21220411 is an equidigital number, since it uses as much as digits as its factorization.

21220411 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 517612.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 21220411 is about 4606.5617330065. The cubic root of 21220411 is about 276.8542939469.

Adding to 21220411 its reverse (11402212), we get a palindrome (32622623).

The spelling of 21220411 in words is "twenty-one million, two hundred twenty thousand, four hundred eleven".