21226268 has 48 divisors (see below), whose sum is σ = 47335680. Its totient is φ = 8107776.

The previous prime is 21226241. The next prime is 21226277. The reversal of 21226268 is 86262212.

It is a self number, because there is not a number n which added to its sum of digits gives 21226268.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7871 + ... + 10217.

It is an arithmetic number, because the mean of its divisors is an integer number (986160).

Almost surely, 2^21226268 is an apocalyptic number.

21226268 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21226268, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23667840).

21226268 is an abundant number, since it is smaller than the sum of its proper divisors (26109412).

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

21226268 is a wasteful number, since it uses less digits than its factorization.

21226268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2394 (or 2392 counting only the distinct ones).

The product of its digits is 4608, while the sum is 29.

The square root of 21226268 is about 4607.1974127445. The cubic root of 21226268 is about 276.8797629232.

The spelling of 21226268 in words is "twenty-one million, two hundred twenty-six thousand, two hundred sixty-eight".