21830533 has 8 divisors (see below), whose sum is σ = 23912280. Its totient is φ = 19837440.

The previous prime is 21830527. The next prime is 21830569. The reversal of 21830533 is 33503812.

It can be written as a sum of positive squares in 4 ways, for example, as 3323329 + 18507204 = 1823^2 + 4302^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21830533 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21830498 and 21830507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21836533) 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, 21648 + ... + 22633.

It is an arithmetic number, because the mean of its divisors is an integer number (2989035).

Almost surely, 2^21830533 is an apocalyptic number.

It is an amenable number.

21830533 is a deficient number, since it is larger than the sum of its proper divisors (2081747).

21830533 is a wasteful number, since it uses less digits than its factorization.

21830533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44327.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 21830533 is about 4672.3155929368. The cubic root of 21830533 is about 279.4826031929.

The spelling of 21830533 in words is "twenty-one million, eight hundred thirty thousand, five hundred thirty-three".