2001309697 has 4 divisors (see below), whose sum is σ = 2008749780. Its totient is φ = 1993869616.

The previous prime is 2001309689. The next prime is 2001309707. The reversal of 2001309697 is 7969031002.

It is a Cunningham number, because it is equal to 44736²+1.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7969031002 = 2 ⋅3984515501.

It can be written as a sum of positive squares in 2 ways, for example, as 131698576 + 1869611121 = 11476^2 + 43239^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001309697 - 2³ = 2001309689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2001303697) 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, 3719638 + ... + 3720175.

It is an arithmetic number, because the mean of its divisors is an integer number (502187445).

Almost surely, 2^2001309697 is an apocalyptic number.

It is an amenable number.

2001309697 is a deficient number, since it is larger than the sum of its proper divisors (7440083).

2001309697 is an equidigital number, since it uses as much as digits as its factorization.

2001309697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7440082.

The product of its (nonzero) digits is 20412, while the sum is 37.

The square root of 2001309697 is about 44736.0000111767. Note that the first 4 decimals coincide. The cubic root of 2001309697 is about 1260.1960090213.

The spelling of 2001309697 in words is "two billion, one million, three hundred nine thousand, six hundred ninety-seven".