21443136 has 168 divisors, whose sum is σ = 68104512. Its totient is φ = 5913600.

The previous prime is 21443131. The next prime is 21443141. The reversal of 21443136 is 63134412.

It is an interprime number because it is at equal distance from previous prime (21443131) and next prime (21443141).

It is a Harshad number since it is a multiple of its sum of digits (24).

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

It is a zygodrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (21443131) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 301981 + ... + 302051.

It is an arithmetic number, because the mean of its divisors is an integer number (405384).

Almost surely, 2^21443136 is an apocalyptic number.

21443136 is a gapful number since it is divisible by the number (26) 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 21443136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34052256).

21443136 is an abundant number, since it is smaller than the sum of its proper divisors (46661376).

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

21443136 is a wasteful number, since it uses less digits than its factorization.

21443136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121 (or 100 counting only the distinct ones).

The product of its digits is 1728, while the sum is 24.

The square root of 21443136 is about 4630.6733851568. The cubic root of 21443136 is about 277.8195264303.

Adding to 21443136 its reverse (63134412), we get a palindrome (84577548).

The spelling of 21443136 in words is "twenty-one million, four hundred forty-three thousand, one hundred thirty-six".