21231120203 has 4 divisors (see below), whose sum is σ = 21499868640. Its totient is φ = 20962371768.

The previous prime is 21231120187. The next prime is 21231120223. The reversal of 21231120203 is 30202113212.

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 21231120203 - 2⁴ = 21231120187 is a prime.

It is a super-2 number, since 2×21231120203² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21231120223) 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, 134374100 + ... + 134374257.

It is an arithmetic number, because the mean of its divisors is an integer number (5374967160).

Almost surely, 2^21231120203 is an apocalyptic number.

21231120203 is a deficient number, since it is larger than the sum of its proper divisors (268748437).

21231120203 is an equidigital number, since it uses as much as digits as its factorization.

21231120203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268748436.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21231120203 its reverse (30202113212), we get a palindrome (51433233415).

The spelling of 21231120203 in words is "twenty-one billion, two hundred thirty-one million, one hundred twenty thousand, two hundred three".