1668539 has 2 divisors, whose sum is σ = 1668540. Its totient is φ = 1668538.

The previous prime is 1668521. The next prime is 1668551. The reversal of 1668539 is 9358661.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1668539 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1668509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 834269 + 834270.

It is an arithmetic number, because the mean of its divisors is an integer number (834270).

2^1668539 is an apocalyptic number.

1668539 is a deficient number, since it is larger than the sum of its proper divisors (1).

1668539 is an equidigital number, since it uses as much as digits as its factorization.

1668539 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38880, while the sum is 38.

The square root of 1668539 is about 1291.7193967732. The cubic root of 1668539 is about 118.6074914671.

The spelling of 1668539 in words is "one million, six hundred sixty-eight thousand, five hundred thirty-nine".