2001221111 has 4 divisors (see below), whose sum is σ = 2050031424. Its totient is φ = 1952410800.

The previous prime is 2001221077. The next prime is 2001221119. The reversal of 2001221111 is 1111221002.

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

It is a cyclic number.

It is not a de Polignac number, because 2001221111 - 2²² = 1997026807 is a prime.

It is a super-2 number, since 2×2001221111² = 8009771870224148642, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2001221092 and 2001221101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001221119) 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, 24405095 + ... + 24405176.

It is an arithmetic number, because the mean of its divisors is an integer number (512507856).

Almost surely, 2^2001221111 is an apocalyptic number.

2001221111 is a deficient number, since it is larger than the sum of its proper divisors (48810313).

2001221111 is an equidigital number, since it uses as much as digits as its factorization.

2001221111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48810312.

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 2001221111 is about 44735.0099027596. The cubic root of 2001221111 is about 1260.1774149691.

Adding to 2001221111 its reverse (1111221002), we get a palindrome (3112442113).

The spelling of 2001221111 in words is "two billion, one million, two hundred twenty-one thousand, one hundred eleven".