2001011989 has 4 divisors (see below), whose sum is σ = 2002254156. Its totient is φ = 1999769824.

The previous prime is 2001011941. The next prime is 2001012001. The reversal of 2001011989 is 9891101002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9891101002 = 2 ⋅4945550501.

It can be written as a sum of positive squares in 2 ways, for example, as 636300625 + 1364711364 = 25225^2 + 36942^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2001011989 is a prime.

It is a super-2 number, since 2×2001011989² = 8008097960243472242, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2001011989.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001012989) 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, 618664 + ... + 621889.

It is an arithmetic number, because the mean of its divisors is an integer number (500563539).

Almost surely, 2^2001011989 is an apocalyptic number.

It is an amenable number.

2001011989 is a deficient number, since it is larger than the sum of its proper divisors (1242167).

2001011989 is a wasteful number, since it uses less digits than its factorization.

2001011989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1242166.

The product of its (nonzero) digits is 1296, while the sum is 31.

The square root of 2001011989 is about 44732.6725000866. The cubic root of 2001011989 is about 1260.1335184368.

The spelling of 2001011989 in words is "two billion, one million, eleven thousand, nine hundred eighty-nine".