1689390078797 has 2 divisors, whose sum is σ = 1689390078798. Its totient is φ = 1689390078796.

The previous prime is 1689390078763. The next prime is 1689390078799. The reversal of 1689390078797 is 7978700939861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1272731447716 + 416658631081 = 1128154^2 + 645491^2 .

It is an emirp because it is prime and its reverse (7978700939861) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1689390078797 - 2³⁴ = 1672210209613 is a prime.

Together with 1689390078799, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1689390078799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 844695039398 + 844695039399.

It is an arithmetic number, because the mean of its divisors is an integer number (844695039399).

Almost surely, 2^{1689390078797} is an apocalyptic number.

It is an amenable number.

1689390078797 is a deficient number, since it is larger than the sum of its proper divisors (1).

1689390078797 is an equidigital number, since it uses as much as digits as its factorization.

1689390078797 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288054144, while the sum is 74.

The spelling of 1689390078797 in words is "one trillion, six hundred eighty-nine billion, three hundred ninety million, seventy-eight thousand, seven hundred ninety-seven".