21443036 has 6 divisors (see below), whose sum is σ = 37525320. Its totient is φ = 10721516.

The previous prime is 21443033. The next prime is 21443047. The reversal of 21443036 is 63034412.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21443033) 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 as a sum of consecutive naturals, namely, 2680376 + ... + 2680383.

It is an arithmetic number, because the mean of its divisors is an integer number (6254220).

Almost surely, 2^21443036 is an apocalyptic number.

It is an amenable number.

21443036 is a deficient number, since it is larger than the sum of its proper divisors (16082284).

21443036 is a wasteful number, since it uses less digits than its factorization.

21443036 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5360763 (or 5360761 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 23.

The square root of 21443036 is about 4630.6625875786. The cubic root of 21443036 is about 277.8190945594.

Adding to 21443036 its reverse (63034412), we get a palindrome (84477448).

The spelling of 21443036 in words is "twenty-one million, four hundred forty-three thousand, thirty-six".