21320226 has 16 divisors (see below), whose sum is σ = 47378400. Its totient is φ = 7106724.

The previous prime is 21320213. The next prime is 21320239. The reversal of 21320226 is 62202312.

It is an interprime number because it is at equal distance from previous prime (21320213) and next prime (21320239).

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 = 21320199 and 21320208.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 197356 + ... + 197463.

It is an arithmetic number, because the mean of its divisors is an integer number (2961150).

Almost surely, 2^21320226 is an apocalyptic number.

21320226 is an abundant number, since it is smaller than the sum of its proper divisors (26058174).

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

21320226 is a wasteful number, since it uses less digits than its factorization.

21320226 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 394830 (or 394824 counting only the distinct ones).

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

The square root of 21320226 is about 4617.3830250478. The cubic root of 21320226 is about 277.2876973700.

Adding to 21320226 its reverse (62202312), we get a palindrome (83522538).

The spelling of 21320226 in words is "twenty-one million, three hundred twenty thousand, two hundred twenty-six".