21468128 has 48 divisors (see below), whose sum is σ = 46811520. Its totient is φ = 9609600.

The previous prime is 21468121. The next prime is 21468163. The reversal of 21468128 is 82186412.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 21468094 and 21468103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21468121) 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, 24563 + ... + 25421.

It is an arithmetic number, because the mean of its divisors is an integer number (975240).

Almost surely, 2^21468128 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21468128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23405760).

21468128 is an abundant number, since it is smaller than the sum of its proper divisors (25343392).

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

21468128 is a wasteful number, since it uses less digits than its factorization.

21468128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 951 (or 943 counting only the distinct ones).

The product of its digits is 6144, while the sum is 32.

The square root of 21468128 is about 4633.3711269442. The cubic root of 21468128 is about 277.9274175193.

The spelling of 21468128 in words is "twenty-one million, four hundred sixty-eight thousand, one hundred twenty-eight".