21433444 has 12 divisors (see below), whose sum is σ = 39482800. Its totient is φ = 10152648.

The previous prime is 21433441. The next prime is 21433453. The reversal of 21433444 is 44433412.

It is a super-2 number, since 2×21433444² = 918785043402272, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21433441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 140934 + ... + 141085.

Almost surely, 2^21433444 is an apocalyptic number.

It is an amenable number.

21433444 is a deficient number, since it is larger than the sum of its proper divisors (18049356).

21433444 is a wasteful number, since it uses less digits than its factorization.

21433444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 282042 (or 282040 counting only the distinct ones).

The product of its digits is 4608, while the sum is 25.

The square root of 21433444 is about 4629.6267668139. The cubic root of 21433444 is about 277.7776632651. Note that the first 3 decimals are identical.

Adding to 21433444 its reverse (44433412), we get a palindrome (65866856).

The spelling of 21433444 in words is "twenty-one million, four hundred thirty-three thousand, four hundred forty-four".