2001122001 has 12 divisors (see below), whose sum is σ = 2909910900. Its totient is φ = 1325126880.

The previous prime is 2001121999. The next prime is 2001122069. The reversal of 2001122001 is 1002211002.

It can be written as a sum of positive squares in 2 ways, for example, as 541958400 + 1459163601 = 23280^2 + 38199^2 .

It is not a de Polignac number, because 2001122001 - 2¹ = 2001121999 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (2001122401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 744790 + ... + 747471.

It is an arithmetic number, because the mean of its divisors is an integer number (242492575).

Almost surely, 2^2001122001 is an apocalyptic number.

It is an amenable number.

2001122001 is a deficient number, since it is larger than the sum of its proper divisors (908788899).

2001122001 is a wasteful number, since it uses less digits than its factorization.

2001122001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1492416 (or 1492413 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 2001122001 is about 44733.9021436762. The cubic root of 2001122001 is about 1260.1566112967.

Adding to 2001122001 its reverse (1002211002), we get a palindrome (3003333003).

The spelling of 2001122001 in words is "two billion, one million, one hundred twenty-two thousand, one".