221001220222121 has 4 divisors (see below), whose sum is σ = 221203417131012. Its totient is φ = 220799023313232.

The previous prime is 221001220222103. The next prime is 221001220222193. The reversal of 221001220222121 is 121222022100122.

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 155709568116496 + 65291652105625 = 12478364^2 + 8080325^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221001220222121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221001220222093 and 221001220222102.

It is not an unprimeable number, because it can be changed into a prime (221001220222421) 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, 101098452806 + ... + 101098454991.

It is an arithmetic number, because the mean of its divisors is an integer number (55300854282753).

Almost surely, 2^{221001220222121} is an apocalyptic number.

It is an amenable number.

221001220222121 is a deficient number, since it is larger than the sum of its proper divisors (202196908891).

221001220222121 is a wasteful number, since it uses less digits than its factorization.

221001220222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202196908890.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 221001220222121 its reverse (121222022100122), we get a palindrome (342223242322243).

The spelling of 221001220222121 in words is "two hundred twenty-one trillion, one billion, two hundred twenty million, two hundred twenty-two thousand, one hundred twenty-one".