203131121213021 has 4 divisors (see below), whose sum is σ = 211962909091872. Its totient is φ = 194299333334172.

The previous prime is 203131121212967. The next prime is 203131121213047. The reversal of 203131121213021 is 120312121131302.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 203131121213021 - 2¹⁴ = 203131121196637 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 8831787878827 = 203131121213021 / (2 + 0 + 3 + 1 + 3 + 1 + 1 + 2 + 1 + 2 + 1 + 3 + 0 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (203131121216021) 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, 4415893939391 + ... + 4415893939436.

It is an arithmetic number, because the mean of its divisors is an integer number (52990727272968).

Almost surely, 2^{203131121213021} is an apocalyptic number.

It is an amenable number.

203131121213021 is a deficient number, since it is larger than the sum of its proper divisors (8831787878851).

203131121213021 is an equidigital number, since it uses as much as digits as its factorization.

203131121213021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8831787878850.

The product of its (nonzero) digits is 432, while the sum is 23.

Adding to 203131121213021 its reverse (120312121131302), we get a palindrome (323443242344323).

The spelling of 203131121213021 in words is "two hundred three trillion, one hundred thirty-one billion, one hundred twenty-one million, two hundred thirteen thousand, twenty-one".