21440032 has 12 divisors (see below), whose sum is σ = 42210126. Its totient is φ = 10720000.

The previous prime is 21440017. The next prime is 21440039. The reversal of 21440032 is 23004412.

It can be written as a sum of positive squares in only one way, i.e., 12702096 + 8737936 = 3564^2 + 2956^2 .

It is a super-2 number, since 2×21440032² = 919349944322048, which contains 22 as substring.

It is a hoax number, since the sum of its digits (16) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 21439988 and 21440015.

It is not an unprimeable number, because it can be changed into a prime (21440039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334969 + ... + 335032.

Almost surely, 2^21440032 is an apocalyptic number.

It is an amenable number.

21440032 is a deficient number, since it is larger than the sum of its proper divisors (20770094).

21440032 is an equidigital number, since it uses as much as digits as its factorization.

21440032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 670011 (or 670003 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 21440032 is about 4630.3382165885. The cubic root of 21440032 is about 277.8061205332.

Adding to 21440032 its reverse (23004412), we get a palindrome (44444444).

The spelling of 21440032 in words is "twenty-one million, four hundred forty thousand, thirty-two".