2643887941657 has 2 divisors, whose sum is σ = 2643887941658. Its totient is φ = 2643887941656.

The previous prime is 2643887941631. The next prime is 2643887941729. The reversal of 2643887941657 is 7561497883462.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1477770884496 + 1166117057161 = 1215636^2 + 1079869^2 .

It is a cyclic number.

It is not a de Polignac number, because 2643887941657 - 2⁷ = 2643887941529 is a prime.

It is not a weakly prime, because it can be changed into another prime (2643887041657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1321943970828 + 1321943970829.

It is an arithmetic number, because the mean of its divisors is an integer number (1321943970829).

Almost surely, 2^{2643887941657} is an apocalyptic number.

It is an amenable number.

2643887941657 is a deficient number, since it is larger than the sum of its proper divisors (1).

2643887941657 is an equidigital number, since it uses as much as digits as its factorization.

2643887941657 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 487710720, while the sum is 70.

The spelling of 2643887941657 in words is "two trillion, six hundred forty-three billion, eight hundred eighty-seven million, nine hundred forty-one thousand, six hundred fifty-seven".