203121212123 has 4 divisors (see below), whose sum is σ = 203145491160. Its totient is φ = 203096933088.

The previous prime is 203121212059. The next prime is 203121212143. The reversal of 203121212123 is 321212121302.

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 203121212123 - 2⁶ = 203121212059 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 203121212095 and 203121212104.

It is not an unprimeable number, because it can be changed into a prime (203121212143) 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, 12126965 + ... + 12143702.

It is an arithmetic number, because the mean of its divisors is an integer number (50786372790).

Almost surely, 2^203121212123 is an apocalyptic number.

203121212123 is a deficient number, since it is larger than the sum of its proper divisors (24279037).

203121212123 is an equidigital number, since it uses as much as digits as its factorization.

203121212123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24279036.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 203121212123 its reverse (321212121302), we get a palindrome (524333333425).

The spelling of 203121212123 in words is "two hundred three billion, one hundred twenty-one million, two hundred twelve thousand, one hundred twenty-three".