21830399 has 4 divisors (see below), whose sum is σ = 21844680. Its totient is φ = 21816120.

The previous prime is 21830387. The next prime is 21830453. The reversal of 21830399 is 99303812.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21830399 - 2⁸ = 21830143 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21830339) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4529 + ... + 8010.

It is an arithmetic number, because the mean of its divisors is an integer number (5461170).

Almost surely, 2^21830399 is an apocalyptic number.

21830399 is a deficient number, since it is larger than the sum of its proper divisors (14281).

21830399 is a wasteful number, since it uses less digits than its factorization.

21830399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14280.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 21830399 is about 4672.3012531300. The cubic root of 21830399 is about 279.4820313524.

The spelling of 21830399 in words is "twenty-one million, eight hundred thirty thousand, three hundred ninety-nine".