77789189 has 2 divisors, whose sum is σ = 77789190. Its totient is φ = 77789188.

The previous prime is 77789149. The next prime is 77789203. The reversal of 77789189 is 98198777.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59938564 + 17850625 = 7742^2 + 4225^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77789189 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77789119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38894594 + 38894595.

It is an arithmetic number, because the mean of its divisors is an integer number (38894595).

Almost surely, 2^77789189 is an apocalyptic number.

It is an amenable number.

77789189 is a deficient number, since it is larger than the sum of its proper divisors (1).

77789189 is an equidigital number, since it uses as much as digits as its factorization.

77789189 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1778112, while the sum is 56.

The square root of 77789189 is about 8819.8179686431. The cubic root of 77789189 is about 426.8805963180.

The spelling of 77789189 in words is "seventy-seven million, seven hundred eighty-nine thousand, one hundred eighty-nine".