2001121243 has 4 divisors (see below), whose sum is σ = 2183041368. Its totient is φ = 1819201120.

The previous prime is 2001121223. The next prime is 2001121259. The reversal of 2001121243 is 3421211002.

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

It is not a de Polignac number, because 2001121243 - 2¹⁷ = 2000990171 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2001121223) 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, 90960046 + ... + 90960067.

It is an arithmetic number, because the mean of its divisors is an integer number (545760342).

Almost surely, 2^2001121243 is an apocalyptic number.

2001121243 is a deficient number, since it is larger than the sum of its proper divisors (181920125).

2001121243 is a wasteful number, since it uses less digits than its factorization.

2001121243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181920124.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 2001121243 is about 44733.8936713539. The cubic root of 2001121243 is about 1260.1564521861.

Adding to 2001121243 its reverse (3421211002), we get a palindrome (5422332245).

The spelling of 2001121243 in words is "two billion, one million, one hundred twenty-one thousand, two hundred forty-three".