6659021539 has 4 divisors (see below), whose sum is σ = 6659997840. Its totient is φ = 6658045240.

The previous prime is 6659021521. The next prime is 6659021549. The reversal of 6659021539 is 9351209566.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9351209566 = 2 ⋅4675604783.

It is a cyclic number.

It is not a de Polignac number, because 6659021539 - 2¹¹ = 6659019491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6659021549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 477847 + ... + 491584.

It is an arithmetic number, because the mean of its divisors is an integer number (1664999460).

Almost surely, 2^6659021539 is an apocalyptic number.

6659021539 is a deficient number, since it is larger than the sum of its proper divisors (976301).

6659021539 is an equidigital number, since it uses as much as digits as its factorization.

6659021539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 976300.

The product of its (nonzero) digits is 437400, while the sum is 46.

The square root of 6659021539 is about 81602.8280085929. The cubic root of 6659021539 is about 1881.3523485205.

The spelling of 6659021539 in words is "six billion, six hundred fifty-nine million, twenty-one thousand, five hundred thirty-nine".