203121220 has 48 divisors (see below), whose sum is σ = 447935040. Its totient is φ = 77261184.

The previous prime is 203121197. The next prime is 203121221. The reversal of 203121220 is 22121302.

It is a self number, because there is not a number n which added to its sum of digits gives 203121220.

It is not an unprimeable number, because it can be changed into a prime (203121221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36247 + ... + 41473.

It is an arithmetic number, because the mean of its divisors is an integer number (9331980).

Almost surely, 2^203121220 is an apocalyptic number.

203121220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 203121220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (223967520).

203121220 is an abundant number, since it is smaller than the sum of its proper divisors (244813820).

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

203121220 is a wasteful number, since it uses less digits than its factorization.

203121220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5332 (or 5330 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 203121220 is about 14252.0602019498. The cubic root of 203121220 is about 587.8300255301.

Adding to 203121220 its reverse (22121302), we get a palindrome (225242522).

The spelling of 203121220 in words is "two hundred three million, one hundred twenty-one thousand, two hundred twenty".