2001220201021 has 4 divisors (see below), whose sum is σ = 2021851337212. Its totient is φ = 1980589064832.

The previous prime is 2001220201007. The next prime is 2001220201073. The reversal of 2001220201021 is 1201020221002.

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 1573845520900 + 427374680121 = 1254530^2 + 653739^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001220201021 - 2⁵ = 2001220200989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2001220200992 and 2001220201010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001220201091) 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, 10315567950 + ... + 10315568143.

It is an arithmetic number, because the mean of its divisors is an integer number (505462834303).

Almost surely, 2^{2001220201021} is an apocalyptic number.

It is an amenable number.

2001220201021 is a deficient number, since it is larger than the sum of its proper divisors (20631136191).

2001220201021 is an equidigital number, since it uses as much as digits as its factorization.

2001220201021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20631136190.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 2001220201021 its reverse (1201020221002), we get a palindrome (3202240422023).

The spelling of 2001220201021 in words is "two trillion, one billion, two hundred twenty million, two hundred one thousand, twenty-one".