21443316 has 12 divisors (see below), whose sum is σ = 50034432. Its totient is φ = 7147768.

The previous prime is 21443311. The next prime is 21443321. The reversal of 21443316 is 61334412.

It is an interprime number because it is at equal distance from previous prime (21443311) and next prime (21443321).

It is a tau number, because it is divible by the number of its divisors (12).

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 (21443311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 893460 + ... + 893483.

It is an arithmetic number, because the mean of its divisors is an integer number (4169536).

Almost surely, 2^21443316 is an apocalyptic number.

It is an amenable number.

21443316 is an abundant number, since it is smaller than the sum of its proper divisors (28591116).

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

21443316 is a wasteful number, since it uses less digits than its factorization.

21443316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1786950 (or 1786948 counting only the distinct ones).

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

The square root of 21443316 is about 4630.6928207343. The cubic root of 21443316 is about 277.8203037944.

Adding to 21443316 its reverse (61334412), we get a palindrome (82777728).

It can be divided in two parts, 2144 and 3316, that added together give a triangular number (5460 = T₁₀₄).

The spelling of 21443316 in words is "twenty-one million, four hundred forty-three thousand, three hundred sixteen".