2001221010221 has 4 divisors (see below), whose sum is σ = 2001285933600. Its totient is φ = 2001156086844.

The previous prime is 2001221010209. The next prime is 2001221010233. The reversal of 2001221010221 is 1220101221002.

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 an interprime number because it is at equal distance from previous prime (2001221010209) and next prime (2001221010233).

It is a cyclic number.

It is not a de Polignac number, because 2001221010221 - 2¹⁸ = 2001220748077 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2001221010196 and 2001221010205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001221010251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32415431 + ... + 32477108.

It is an arithmetic number, because the mean of its divisors is an integer number (500321483400).

Almost surely, 2^{2001221010221} is an apocalyptic number.

It is an amenable number.

2001221010221 is a deficient number, since it is larger than the sum of its proper divisors (64923379).

2001221010221 is an equidigital number, since it uses as much as digits as its factorization.

2001221010221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64923378.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 2001221010221 its reverse (1220101221002), we get a palindrome (3221322231223).

The spelling of 2001221010221 in words is "two trillion, one billion, two hundred twenty-one million, ten thousand, two hundred twenty-one".