21324726 has 48 divisors (see below), whose sum is σ = 50768640. Its totient is φ = 6438960.

The previous prime is 21324713. The next prime is 21324727. The reversal of 21324726 is 62742312.

It is a self number, because there is not a number n which added to its sum of digits gives 21324726.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21324727) 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 23 ways as a sum of consecutive naturals, for example, 6511 + ... + 9221.

It is an arithmetic number, because the mean of its divisors is an integer number (1057680).

Almost surely, 2^21324726 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21324726, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25384320).

21324726 is an abundant number, since it is smaller than the sum of its proper divisors (29443914).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21324726 is a wasteful number, since it uses less digits than its factorization.

21324726 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2761 (or 2758 counting only the distinct ones).

The product of its digits is 4032, while the sum is 27.

The square root of 21324726 is about 4617.8702883472. The cubic root of 21324726 is about 277.3072047751.

The spelling of 21324726 in words is "twenty-one million, three hundred twenty-four thousand, seven hundred twenty-six".