203121212111 has 4 divisors (see below), whose sum is σ = 203643375000. Its totient is φ = 202599049224.

The previous prime is 203121212059. The next prime is 203121212143. The reversal of 203121212111 is 111212121302.

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-203121212111 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 203121212111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (203121217111) 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, 261080861 + ... + 261081638.

It is an arithmetic number, because the mean of its divisors is an integer number (50910843750).

Almost surely, 2^203121212111 is an apocalyptic number.

203121212111 is a deficient number, since it is larger than the sum of its proper divisors (522162889).

203121212111 is an equidigital number, since it uses as much as digits as its factorization.

203121212111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 522162888.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 203121212111 its reverse (111212121302), we get a palindrome (314333333413).

The spelling of 203121212111 in words is "two hundred three billion, one hundred twenty-one million, two hundred twelve thousand, one hundred eleven".