21443144 has 8 divisors (see below), whose sum is σ = 40205910. Its totient is φ = 10721568.

The previous prime is 21443141. The next prime is 21443159. The reversal of 21443144 is 44134412.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 17322244 + 4120900 = 4162^2 + 2030^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (21443141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1340189 + ... + 1340204.

Almost surely, 2^21443144 is an apocalyptic number.

It is an amenable number.

21443144 is a deficient number, since it is larger than the sum of its proper divisors (18762766).

21443144 is a wasteful number, since it uses less digits than its factorization.

21443144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2680399 (or 2680395 counting only the distinct ones).

The product of its digits is 1536, while the sum is 23.

The square root of 21443144 is about 4630.6742489620. The cubic root of 21443144 is about 277.8195609799.

Adding to 21443144 its reverse (44134412), we get a palindrome (65577556).

The spelling of 21443144 in words is "twenty-one million, four hundred forty-three thousand, one hundred forty-four".