1678079989 has 2 divisors, whose sum is σ = 1678079990. Its totient is φ = 1678079988.

The previous prime is 1678079987. The next prime is 1678080067. The reversal of 1678079989 is 9899708761.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1523575089 + 154504900 = 39033^2 + 12430^2 .

It is a cyclic number.

It is not a de Polignac number, because 1678079989 - 2¹ = 1678079987 is a prime.

Together with 1678079987, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1678079989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1678079987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 839039994 + 839039995.

It is an arithmetic number, because the mean of its divisors is an integer number (839039995).

Almost surely, 2^1678079989 is an apocalyptic number.

It is an amenable number.

1678079989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1678079989 is an equidigital number, since it uses as much as digits as its factorization.

1678079989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13716864, while the sum is 64.

The square root of 1678079989 is about 40964.3746321117. The cubic root of 1678079989 is about 1188.3313450804.

It can be divided in two parts, 16780 and 79989, that added together give a palindrome (96769).

The spelling of 1678079989 in words is "one billion, six hundred seventy-eight million, seventy-nine thousand, nine hundred eighty-nine".