21220326 has 16 divisors (see below), whose sum is σ = 47156400. Its totient is φ = 7073424.

The previous prime is 21220319. The next prime is 21220327. The reversal of 21220326 is 62302212.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21220299 and 21220308.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220327) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 196431 + ... + 196538.

It is an arithmetic number, because the mean of its divisors is an integer number (2947275).

Almost surely, 2^21220326 is an apocalyptic number.

21220326 is an abundant number, since it is smaller than the sum of its proper divisors (25936074).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21220326 is a wasteful number, since it uses less digits than its factorization.

21220326 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 392980 (or 392974 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 21220326 is about 4606.5525070274. The cubic root of 21220326 is about 276.8539242926.

Adding to 21220326 its reverse (62302212), we get a palindrome (83522538).

The spelling of 21220326 in words is "twenty-one million, two hundred twenty thousand, three hundred twenty-six".