6646475861777 has 2 divisors, whose sum is σ = 6646475861778. Its totient is φ = 6646475861776.

The previous prime is 6646475861771. The next prime is 6646475861783. The reversal of 6646475861777 is 7771685746466.

It is a Cunningham number, because it is equal to 2578076²+1.

It is a balanced prime because it is at equal distance from previous prime (6646475861771) and next prime (6646475861783).

It can be written as a sum of positive squares in only one way, i.e., 6646475861776 + 1 = 2578076^2 + 1^2 .

It is a cyclic number.

It is not a de Polignac number, because 6646475861777 - 2⁸ = 6646475861521 is a prime.

It is not a weakly prime, because it can be changed into another prime (6646475861771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3323237930888 + 3323237930889.

It is an arithmetic number, because the mean of its divisors is an integer number (3323237930889).

Almost surely, 2^{6646475861777} is an apocalyptic number.

It is an amenable number.

6646475861777 is a deficient number, since it is larger than the sum of its proper divisors (1).

6646475861777 is an equidigital number, since it uses as much as digits as its factorization.

6646475861777 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1991485440, while the sum is 74.

The spelling of 6646475861777 in words is "six trillion, six hundred forty-six billion, four hundred seventy-five million, eight hundred sixty-one thousand, seven hundred seventy-seven".