21051450203 has 4 divisors (see below), whose sum is σ = 24058800240. Its totient is φ = 18044100168.

The previous prime is 21051450191. The next prime is 21051450253. The reversal of 21051450203 is 30205415012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21051450203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21051450253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1503675008 + ... + 1503675021.

It is an arithmetic number, because the mean of its divisors is an integer number (6014700060).

Almost surely, 2^21051450203 is an apocalyptic number.

21051450203 is a deficient number, since it is larger than the sum of its proper divisors (3007350037).

21051450203 is an equidigital number, since it uses as much as digits as its factorization.

21051450203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3007350036.

The product of its (nonzero) digits is 1200, while the sum is 23.

Adding to 21051450203 its reverse (30205415012), we get a palindrome (51256865215).

The spelling of 21051450203 in words is "twenty-one billion, fifty-one million, four hundred fifty thousand, two hundred three".