1797720689 has 2 divisors, whose sum is σ = 1797720690. Its totient is φ = 1797720688.

The previous prime is 1797720679. The next prime is 1797720763. The reversal of 1797720689 is 9860277971.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1445520400 + 352200289 = 38020^2 + 18767^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1797720689 is a prime.

It is not a weakly prime, because it can be changed into another prime (1797720679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 898860344 + 898860345.

It is an arithmetic number, because the mean of its divisors is an integer number (898860345).

Almost surely, 2^1797720689 is an apocalyptic number.

It is an amenable number.

1797720689 is a deficient number, since it is larger than the sum of its proper divisors (1).

1797720689 is an equidigital number, since it uses as much as digits as its factorization.

1797720689 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2667168, while the sum is 56.

The square root of 1797720689 is about 42399.5364243526. The cubic root of 1797720689 is about 1215.9267292766.

The spelling of 1797720689 in words is "one billion, seven hundred ninety-seven million, seven hundred twenty thousand, six hundred eighty-nine".