21226770 has 48 divisors (see below), whose sum is σ = 55486080. Its totient is φ = 5630112.

The previous prime is 21226759. The next prime is 21226771. The reversal of 21226770 is 7762212.

It is not an unprimeable number, because it can be changed into a prime (21226771) 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 23 ways as a sum of consecutive naturals, for example, 19911 + ... + 20949.

It is an arithmetic number, because the mean of its divisors is an integer number (1155960).

Almost surely, 2^21226770 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21226770, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27743040).

21226770 is an abundant number, since it is smaller than the sum of its proper divisors (34259310).

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

21226770 is a wasteful number, since it uses less digits than its factorization.

21226770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1279 (or 1276 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 27.

The square root of 21226770 is about 4607.2518923975. The cubic root of 21226770 is about 276.8819456361.

Adding to 21226770 its reverse (7762212), we get a palindrome (28988982).

The spelling of 21226770 in words is "twenty-one million, two hundred twenty-six thousand, seven hundred seventy".