21426328 has 48 divisors (see below), whose sum is σ = 50992200. Its totient is φ = 8346240.

The previous prime is 21426289. The next prime is 21426329. The reversal of 21426328 is 82362412.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 21426296 and 21426305.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21426329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1828 + ... + 6796.

Almost surely, 2^21426328 is an apocalyptic number.

21426328 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21426328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25496100).

21426328 is an abundant number, since it is smaller than the sum of its proper divisors (29565872).

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

21426328 is a wasteful number, since it uses less digits than its factorization.

21426328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5000 (or 4989 counting only the distinct ones).

The product of its digits is 4608, while the sum is 28.

The square root of 21426328 is about 4628.8581745394. The cubic root of 21426328 is about 277.7469187171.

The spelling of 21426328 in words is "twenty-one million, four hundred twenty-six thousand, three hundred twenty-eight".