2001609811 has 2 divisors, whose sum is σ = 2001609812. Its totient is φ = 2001609810.

The previous prime is 2001609809. The next prime is 2001609839. The reversal of 2001609811 is 1189061002.

It is a happy number.

It is an a-pointer prime, because the next prime (2001609839) can be obtained adding 2001609811 to its sum of digits (28).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2001609811 - 2¹ = 2001609809 is a prime.

It is a super-3 number, since 3×2001609811³ (a number of 29 digits) contains 333 as substring.

Together with 2001609809, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 2001609811.

It is not a weakly prime, because it can be changed into another prime (2001609871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000804905 + 1000804906.

It is an arithmetic number, because the mean of its divisors is an integer number (1000804906).

Almost surely, 2^2001609811 is an apocalyptic number.

2001609811 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001609811 is an equidigital number, since it uses as much as digits as its factorization.

2001609811 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 28.

The square root of 2001609811 is about 44739.3541638679. The cubic root of 2001609811 is about 1260.2589983664.

The spelling of 2001609811 in words is "two billion, one million, six hundred nine thousand, eight hundred eleven".