21443212 has 24 divisors (see below), whose sum is σ = 43029504. Its totient is φ = 9159312.

The previous prime is 21443203. The next prime is 21443221. The reversal of 21443212 is 21234412.

It is an interprime number because it is at equal distance from previous prime (21443203) and next prime (21443221).

It is a super-2 number, since 2×21443212² = 919622681753888, which contains 22 as substring.

It is a plaindrome in base 11.

It is a self number, because there is not a number n which added to its sum of digits gives 21443212.

It is an unprimeable number.

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, 8613 + ... + 10819.

It is an arithmetic number, because the mean of its divisors is an integer number (1792896).

Almost surely, 2^21443212 is an apocalyptic number.

It is an amenable number.

21443212 is an abundant number, since it is smaller than the sum of its proper divisors (21586292).

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

21443212 is a wasteful number, since it uses less digits than its factorization.

21443212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2565 (or 2563 counting only the distinct ones).

The product of its digits is 384, while the sum is 19.

The square root of 21443212 is about 4630.6815912995. The cubic root of 21443212 is about 277.8198546512.

Adding to 21443212 its reverse (21234412), we get a palindrome (42677624).

It can be divided in two parts, 2144 and 3212, that added together give a triangular number (5356 = T₁₀₃).

The spelling of 21443212 in words is "twenty-one million, four hundred forty-three thousand, two hundred twelve".