21203830 has 8 divisors (see below), whose sum is σ = 38166912. Its totient is φ = 8481528.

The previous prime is 21203827. The next prime is 21203851. The reversal of 21203830 is 3830212.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 21203798 and 21203807.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1060182 + ... + 1060201.

It is an arithmetic number, because the mean of its divisors is an integer number (4770864).

Almost surely, 2^21203830 is an apocalyptic number.

21203830 is a deficient number, since it is larger than the sum of its proper divisors (16963082).

21203830 is a wasteful number, since it uses less digits than its factorization.

21203830 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2120390.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 21203830 is about 4604.7616659280. The cubic root of 21203830 is about 276.7821665786.

The spelling of 21203830 in words is "twenty-one million, two hundred three thousand, eight hundred thirty".