2001539 has 2 divisors, whose sum is σ = 2001540. Its totient is φ = 2001538.

The previous prime is 2001533. The next prime is 2001541. The reversal of 2001539 is 9351002.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2001539 is a prime.

It is a Sophie Germain prime.

Together with 2001541, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2001539.

It is not a weakly prime, because it can be changed into another prime (2001533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000769 + 1000770.

It is an arithmetic number, because the mean of its divisors is an integer number (1000770).

2^2001539 is an apocalyptic number.

2001539 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001539 is an equidigital number, since it uses as much as digits as its factorization.

2001539 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 270, while the sum is 20.

The square root of 2001539 is about 1414.7575764066. The cubic root of 2001539 is about 126.0244136787.

The spelling of 2001539 in words is "two million, one thousand, five hundred thirty-nine".