21226368 has 64 divisors (see below), whose sum is σ = 56891520. Its totient is φ = 7011840.

The previous prime is 21226367. The next prime is 21226379. The reversal of 21226368 is 86362212.

It is a tau number, because it is divible by the number of its divisors (64).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21226367) 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, 63963 + ... + 64293.

It is an arithmetic number, because the mean of its divisors is an integer number (888930).

Almost surely, 2^21226368 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21226368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28445760).

21226368 is an abundant number, since it is smaller than the sum of its proper divisors (35665152).

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

21226368 is a wasteful number, since it uses less digits than its factorization.

21226368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 515 (or 503 counting only the distinct ones).

The product of its digits is 6912, while the sum is 30.

The square root of 21226368 is about 4607.2082653164. The cubic root of 21226368 is about 276.8801977293.

The spelling of 21226368 in words is "twenty-one million, two hundred twenty-six thousand, three hundred sixty-eight".