21322021 has 8 divisors (see below), whose sum is σ = 24677120. Its totient is φ = 18044208.

The previous prime is 21322019. The next prime is 21322031. The reversal of 21322021 is 12022312.

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

It is not a de Polignac number, because 21322021 - 2¹ = 21322019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21321992 and 21322010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21322031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18726 + ... + 19831.

It is an arithmetic number, because the mean of its divisors is an integer number (3084640).

Almost surely, 2^21322021 is an apocalyptic number.

It is an amenable number.

21322021 is a deficient number, since it is larger than the sum of its proper divisors (3355099).

21322021 is an equidigital number, since it uses as much as digits as its factorization.

21322021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38643.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21322021 is about 4617.5773951283. The cubic root of 21322021 is about 277.2954789862.

Adding to 21322021 its reverse (12022312), we get a palindrome (33344333).

The spelling of 21322021 in words is "twenty-one million, three hundred twenty-two thousand, twenty-one".