2001311999 has 4 divisors (see below), whose sum is σ = 2003780520. Its totient is φ = 1998843480.

The previous prime is 2001311993. The next prime is 2001312017. The reversal of 2001311999 is 9991131002.

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 2001311999 - 2¹⁶ = 2001246463 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001311993) 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, 1233044 + ... + 1234665.

It is an arithmetic number, because the mean of its divisors is an integer number (500945130).

Almost surely, 2^2001311999 is an apocalyptic number.

2001311999 is a deficient number, since it is larger than the sum of its proper divisors (2468521).

2001311999 is an equidigital number, since it uses as much as digits as its factorization.

2001311999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2468520.

The product of its (nonzero) digits is 4374, while the sum is 35.

The square root of 2001311999 is about 44736.0257398889. The cubic root of 2001311999 is about 1260.1964921999.

The spelling of 2001311999 in words is "two billion, one million, three hundred eleven thousand, nine hundred ninety-nine".