6616001891 has 2 divisors, whose sum is σ = 6616001892. Its totient is φ = 6616001890.

The previous prime is 6616001879. The next prime is 6616001893. The reversal of 6616001891 is 1981006166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6616001891 - 2⁶ = 6616001827 is a prime.

Together with 6616001893, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (6616001893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3308000945 + 3308000946.

It is an arithmetic number, because the mean of its divisors is an integer number (3308000946).

Almost surely, 2^6616001891 is an apocalyptic number.

6616001891 is a deficient number, since it is larger than the sum of its proper divisors (1).

6616001891 is an equidigital number, since it uses as much as digits as its factorization.

6616001891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 38.

The square root of 6616001891 is about 81338.8092548692. The cubic root of 6616001891 is about 1877.2921907605.

The spelling of 6616001891 in words is "six billion, six hundred sixteen million, one thousand, eight hundred ninety-one".