21442368 has 56 divisors (see below), whose sum is σ = 58704480. Its totient is φ = 6899200.

The previous prime is 21442361. The next prime is 21442373. The reversal of 21442368 is 86324412.

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

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21442361) 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 7 ways as a sum of consecutive naturals, for example, 3643 + ... + 7493.

Almost surely, 2^21442368 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 21442368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29352240).

21442368 is an abundant number, since it is smaller than the sum of its proper divisors (37262112).

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

21442368 is a wasteful number, since it uses less digits than its factorization.

21442368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3895 (or 3885 counting only the distinct ones).

The product of its digits is 9216, while the sum is 30.

The square root of 21442368 is about 4630.5904591099. The cubic root of 21442368 is about 277.8162096277.

The spelling of 21442368 in words is "twenty-one million, four hundred forty-two thousand, three hundred sixty-eight".