21354203 has 4 divisors (see below), whose sum is σ = 22996848. Its totient is φ = 19711560.

The previous prime is 21354197. The next prime is 21354241. The reversal of 21354203 is 30245312.

It is a happy number.

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 21354203 - 2⁶ = 21354139 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21354293) 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, 821303 + ... + 821328.

It is an arithmetic number, because the mean of its divisors is an integer number (5749212).

Almost surely, 2^21354203 is an apocalyptic number.

21354203 is a deficient number, since it is larger than the sum of its proper divisors (1642645).

21354203 is a wasteful number, since it uses less digits than its factorization.

21354203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1642644.

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 21354203 is about 4621.0608089485. The cubic root of 21354203 is about 277.4349191319.

Adding to 21354203 its reverse (30245312), we get a palindrome (51599515).

The spelling of 21354203 in words is "twenty-one million, three hundred fifty-four thousand, two hundred three".