6646191896831 has 2 divisors, whose sum is σ = 6646191896832. Its totient is φ = 6646191896830.

The previous prime is 6646191896821. The next prime is 6646191896833. The reversal of 6646191896831 is 1386981916466.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6646191896831 - 2¹⁰ = 6646191895807 is a prime.

It is a super-2 number, since 2×6646191896831² (a number of 26 digits) contains 22 as substring.

Together with 6646191896833, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6646191896833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3323095948415 + 3323095948416.

It is an arithmetic number, because the mean of its divisors is an integer number (3323095948416).

Almost surely, 2^{6646191896831} is an apocalyptic number.

6646191896831 is a deficient number, since it is larger than the sum of its proper divisors (1).

6646191896831 is an equidigital number, since it uses as much as digits as its factorization.

6646191896831 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80621568, while the sum is 68.

The spelling of 6646191896831 in words is "six trillion, six hundred forty-six billion, one hundred ninety-one million, eight hundred ninety-six thousand, eight hundred thirty-one".