680891789 has 2 divisors, whose sum is σ = 680891790. Its totient is φ = 680891788.

The previous prime is 680891779. The next prime is 680891807. The reversal of 680891789 is 987198086.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 678185764 + 2706025 = 26042^2 + 1645^2 .

It is a cyclic number.

It is not a de Polignac number, because 680891789 - 2¹² = 680887693 is a prime.

It is a super-2 number, since 2×680891789² = 927227256655241042, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (680891779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340445894 + 340445895.

It is an arithmetic number, because the mean of its divisors is an integer number (340445895).

Almost surely, 2^680891789 is an apocalyptic number.

It is an amenable number.

680891789 is a deficient number, since it is larger than the sum of its proper divisors (1).

680891789 is an equidigital number, since it uses as much as digits as its factorization.

680891789 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1741824, while the sum is 56.

The square root of 680891789 is about 26093.9032917653. The cubic root of 680891789 is about 879.7501826173.

The spelling of 680891789 in words is "six hundred eighty million, eight hundred ninety-one thousand, seven hundred eighty-nine".