2001320123 has 4 divisors (see below), whose sum is σ = 2183258328. Its totient is φ = 1819381920.

The previous prime is 2001320119. The next prime is 2001320149. The reversal of 2001320123 is 3210231002.

It is a happy number.

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 2001320123 - 2² = 2001320119 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2001320098 and 2001320107.

It is not an unprimeable number, because it can be changed into a prime (2001323123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90969086 + ... + 90969107.

It is an arithmetic number, because the mean of its divisors is an integer number (545814582).

Almost surely, 2^2001320123 is an apocalyptic number.

2001320123 is a deficient number, since it is larger than the sum of its proper divisors (181938205).

2001320123 is a wasteful number, since it uses less digits than its factorization.

2001320123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181938204.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 2001320123 is about 44736.1165391007. The cubic root of 2001320123 is about 1260.1981973850.

Adding to 2001320123 its reverse (3210231002), we get a palindrome (5211551125).

The spelling of 2001320123 in words is "two billion, one million, three hundred twenty thousand, one hundred twenty-three".