6657538891 has 2 divisors, whose sum is σ = 6657538892. Its totient is φ = 6657538890.

The previous prime is 6657538883. The next prime is 6657538897. The reversal of 6657538891 is 1988357566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6657538891 - 2³ = 6657538883 is a prime.

It is not a weakly prime, because it can be changed into another prime (6657538897) 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 as a sum of consecutive naturals, namely, 3328769445 + 3328769446.

It is an arithmetic number, because the mean of its divisors is an integer number (3328769446).

Almost surely, 2^6657538891 is an apocalyptic number.

6657538891 is a deficient number, since it is larger than the sum of its proper divisors (1).

6657538891 is an equidigital number, since it uses as much as digits as its factorization.

6657538891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10886400, while the sum is 58.

The square root of 6657538891 is about 81593.7429647642. The cubic root of 6657538891 is about 1881.2127088689.

The spelling of 6657538891 in words is "six billion, six hundred fifty-seven million, five hundred thirty-eight thousand, eight hundred ninety-one".