203121312121100 has 72 divisors (see below), whose sum is σ = 442201628284416. Its totient is φ = 80985241960000.

The previous prime is 203121312121051. The next prime is 203121312121103. The reversal of 203121312121100 is 1121213121302.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (203121312121103) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2118204155 + ... + 2118300045.

It is an arithmetic number, because the mean of its divisors is an integer number (6141689281728).

Almost surely, 2^{203121312121100} is an apocalyptic number.

203121312121100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

203121312121100 is an abundant number, since it is smaller than the sum of its proper divisors (239080316163316).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

203121312121100 is a wasteful number, since it uses less digits than its factorization.

203121312121100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164327 (or 164320 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 20.

Adding to 203121312121100 its reverse (1121213121302), we get a palindrome (204242525242402).

The spelling of 203121312121100 in words is "two hundred three trillion, one hundred twenty-one billion, three hundred twelve million, one hundred twenty-one thousand, one hundred".