1678620791987 has 2 divisors, whose sum is σ = 1678620791988. Its totient is φ = 1678620791986.

The previous prime is 1678620791983. The next prime is 1678620792049. The reversal of 1678620791987 is 7891970268761.

It is a weak prime.

It is an emirp because it is prime and its reverse (7891970268761) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1678620791987 - 2² = 1678620791983 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1678620791987.

It is not a weakly prime, because it can be changed into another prime (1678620791983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 839310395993 + 839310395994.

It is an arithmetic number, because the mean of its divisors is an integer number (839310395994).

Almost surely, 2^{1678620791987} is an apocalyptic number.

1678620791987 is a deficient number, since it is larger than the sum of its proper divisors (1).

1678620791987 is an equidigital number, since it uses as much as digits as its factorization.

1678620791987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128024064, while the sum is 71.

The spelling of 1678620791987 in words is "one trillion, six hundred seventy-eight billion, six hundred twenty million, seven hundred ninety-one thousand, nine hundred eighty-seven".