21326356 has 24 divisors (see below), whose sum is σ = 38729600. Its totient is φ = 10266912.

The previous prime is 21326351. The next prime is 21326363. The reversal of 21326356 is 65362312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21326351) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14545 + ... + 15943.

Almost surely, 2^21326356 is an apocalyptic number.

It is an amenable number.

21326356 is a deficient number, since it is larger than the sum of its proper divisors (17403244).

21326356 is a wasteful number, since it uses less digits than its factorization.

21326356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1543 (or 1541 counting only the distinct ones).

The product of its digits is 6480, while the sum is 28.

The square root of 21326356 is about 4618.0467732581. The cubic root of 21326356 is about 277.3142701137.

Adding to 21326356 its reverse (65362312), we get a palindrome (86688668).

It can be divided in two parts, 213 and 26356, that added together give a square (26569 = 163²).

The spelling of 21326356 in words is "twenty-one million, three hundred twenty-six thousand, three hundred fifty-six".