21350203 has 4 divisors (see below), whose sum is σ = 24400240. Its totient is φ = 18300168.

The previous prime is 21350201. The next prime is 21350213. The reversal of 21350203 is 30205312.

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 21350203 - 2¹ = 21350201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21350201) 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, 1525008 + ... + 1525021.

It is an arithmetic number, because the mean of its divisors is an integer number (6100060).

Almost surely, 2^21350203 is an apocalyptic number.

21350203 is a deficient number, since it is larger than the sum of its proper divisors (3050037).

21350203 is an equidigital number, since it uses as much as digits as its factorization.

21350203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3050036.

The product of its (nonzero) digits is 180, while the sum is 16.

The square root of 21350203 is about 4620.6279876225. The cubic root of 21350203 is about 277.4175953140.

Adding to 21350203 its reverse (30205312), we get a palindrome (51555515).

The spelling of 21350203 in words is "twenty-one million, three hundred fifty thousand, two hundred three".