21830016 has 64 divisors (see below), whose sum is σ = 62460720. Its totient is φ = 6715392.

The previous prime is 21829981. The next prime is 21830027. The reversal of 21830016 is 61003812.

It is a tau number, because it is divible by the number of its divisors (64).

It is a junction number, because it is equal to n+sod(n) for n = 21829974 and 21830001.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2806 + ... + 7178.

Almost surely, 2^21830016 is an apocalyptic number.

21830016 is a gapful number since it is divisible by the number (26) 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 21830016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31230360).

21830016 is an abundant number, since it is smaller than the sum of its proper divisors (40630704).

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

21830016 is a wasteful number, since it uses less digits than its factorization.

21830016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4403 (or 4391 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 21830016 is about 4672.2602667232. The cubic root of 21830016 is about 279.4803969000.

Adding to 21830016 its reverse (61003812), we get a palindrome (82833828).

The spelling of 21830016 in words is "twenty-one million, eight hundred thirty thousand, sixteen".