203221120021 has 4 divisors (see below), whose sum is σ = 205316183212. Its totient is φ = 201126056832.

The previous prime is 203221119991. The next prime is 203221120043. The reversal of 203221120021 is 120021122302.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 88580640625 + 114640479396 = 297625^2 + 338586^2 .

It is a cyclic number.

It is not a de Polignac number, because 203221120021 - 2⁵ = 203221119989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 203221119977 and 203221120004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (203221121021) 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, 1047531450 + ... + 1047531643.

It is an arithmetic number, because the mean of its divisors is an integer number (51329045803).

Almost surely, 2^203221120021 is an apocalyptic number.

It is an amenable number.

203221120021 is a deficient number, since it is larger than the sum of its proper divisors (2095063191).

203221120021 is an equidigital number, since it uses as much as digits as its factorization.

203221120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2095063190.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 203221120021 its reverse (120021122302), we get a palindrome (323242242323).

The spelling of 203221120021 in words is "two hundred three billion, two hundred twenty-one million, one hundred twenty thousand, twenty-one".