21121031203 has 4 divisors (see below), whose sum is σ = 21123870280. Its totient is φ = 21118192128.

The previous prime is 21121031189. The next prime is 21121031231. The reversal of 21121031203 is 30213012112.

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 21121031203 - 2⁹ = 21121030691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21121031233) 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, 1408350 + ... + 1423267.

It is an arithmetic number, because the mean of its divisors is an integer number (5280967570).

Almost surely, 2^21121031203 is an apocalyptic number.

21121031203 is a deficient number, since it is larger than the sum of its proper divisors (2839077).

21121031203 is an equidigital number, since it uses as much as digits as its factorization.

21121031203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2839076.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21121031203 its reverse (30213012112), we get a palindrome (51334043315).

The spelling of 21121031203 in words is "twenty-one billion, one hundred twenty-one million, thirty-one thousand, two hundred three".