1778318661607 has 2 divisors, whose sum is σ = 1778318661608. Its totient is φ = 1778318661606.

The previous prime is 1778318661601. The next prime is 1778318661667. The reversal of 1778318661607 is 7061668138771.

It is a weak prime.

It is an emirp because it is prime and its reverse (7061668138771) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1778318661607 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1778318661601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 889159330803 + 889159330804.

It is an arithmetic number, because the mean of its divisors is an integer number (889159330804).

Almost surely, 2^{1778318661607} is an apocalyptic number.

1778318661607 is a deficient number, since it is larger than the sum of its proper divisors (1).

1778318661607 is an equidigital number, since it uses as much as digits as its factorization.

1778318661607 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14224896, while the sum is 61.

The spelling of 1778318661607 in words is "one trillion, seven hundred seventy-eight billion, three hundred eighteen million, six hundred sixty-one thousand, six hundred seven".