2001221101 has 4 divisors (see below), whose sum is σ = 2183150304. Its totient is φ = 1819291900.

The previous prime is 2001221077. The next prime is 2001221119. The reversal of 2001221101 is 1011221002.

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 a cyclic number.

It is not a de Polignac number, because 2001221101 - 2¹⁵ = 2001188333 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001221141) 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, 90964585 + ... + 90964606.

It is an arithmetic number, because the mean of its divisors is an integer number (545787576).

Almost surely, 2^2001221101 is an apocalyptic number.

It is an amenable number.

2001221101 is a deficient number, since it is larger than the sum of its proper divisors (181929203).

2001221101 is a wasteful number, since it uses less digits than its factorization.

2001221101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181929202.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 2001221101 is about 44735.0097909903. The cubic root of 2001221101 is about 1260.1774128701.

Adding to 2001221101 its reverse (1011221002), we get a palindrome (3012442103).

Subtracting from 2001221101 its reverse (1011221002), we obtain a palindrome (990000099).

The spelling of 2001221101 in words is "two billion, one million, two hundred twenty-one thousand, one hundred one".