21671324 has 24 divisors (see below), whose sum is σ = 40776960. Its totient is φ = 10045296.

The previous prime is 21671297. The next prime is 21671327. The reversal of 21671324 is 42317612.

It is a junction number, because it is equal to n+sod(n) for n = 21671293 and 21671302.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21671327) 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 in 7 ways as a sum of consecutive naturals, for example, 539 + ... + 6605.

It is an arithmetic number, because the mean of its divisors is an integer number (1699040).

Almost surely, 2^21671324 is an apocalyptic number.

It is an amenable number.

21671324 is a deficient number, since it is larger than the sum of its proper divisors (19105636).

21671324 is a wasteful number, since it uses less digits than its factorization.

21671324 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6137 (or 6135 counting only the distinct ones).

The product of its digits is 2016, while the sum is 26.

The square root of 21671324 is about 4655.2469322260. The cubic root of 21671324 is about 278.8015272036.

Adding to 21671324 its reverse (42317612), we get a palindrome (63988936).

The spelling of 21671324 in words is "twenty-one million, six hundred seventy-one thousand, three hundred twenty-four".