21101111203 has 4 divisors (see below), whose sum is σ = 21104903088. Its totient is φ = 21097319320.

The previous prime is 21101111189. The next prime is 21101111221. The reversal of 21101111203 is 30211110112.

It is a happy number.

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-21101111203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21101111243) 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, 1887583 + ... + 1898728.

It is an arithmetic number, because the mean of its divisors is an integer number (5276225772).

Almost surely, 2^21101111203 is an apocalyptic number.

21101111203 is a deficient number, since it is larger than the sum of its proper divisors (3791885).

21101111203 is an equidigital number, since it uses as much as digits as its factorization.

21101111203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3791884.

The product of its (nonzero) digits is 12, while the sum is 13.

Adding to 21101111203 its reverse (30211110112), we get a palindrome (51312221315).

The spelling of 21101111203 in words is "twenty-one billion, one hundred one million, one hundred eleven thousand, two hundred three".