21323612 has 12 divisors (see below), whose sum is σ = 37385040. Its totient is φ = 10642176.

The previous prime is 21323611. The next prime is 21323633. The reversal of 21323612 is 21632312.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21323611) 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, 2312 + ... + 6927.

It is an arithmetic number, because the mean of its divisors is an integer number (3115420).

Almost surely, 2^21323612 is an apocalyptic number.

It is an amenable number.

21323612 is a deficient number, since it is larger than the sum of its proper divisors (16061428).

21323612 is a wasteful number, since it uses less digits than its factorization.

21323612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9820 (or 9818 counting only the distinct ones).

The product of its digits is 432, while the sum is 20.

The square root of 21323612 is about 4617.7496683991. The cubic root of 21323612 is about 277.3023758642.

Adding to 21323612 its reverse (21632312), we get a palindrome (42955924).

The spelling of 21323612 in words is "twenty-one million, three hundred twenty-three thousand, six hundred twelve".