77438489 has 2 divisors, whose sum is σ = 77438490. Its totient is φ = 77438488.

The previous prime is 77438461. The next prime is 77438507. The reversal of 77438489 is 98483477.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47844889 + 29593600 = 6917^2 + 5440^2 .

It is an emirp because it is prime and its reverse (98483477) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77438489 - 2⁸ = 77438233 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (77438189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38719244 + 38719245.

It is an arithmetic number, because the mean of its divisors is an integer number (38719245).

Almost surely, 2^77438489 is an apocalyptic number.

It is an amenable number.

77438489 is a deficient number, since it is larger than the sum of its proper divisors (1).

77438489 is an equidigital number, since it uses as much as digits as its factorization.

77438489 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1354752, while the sum is 50.

The square root of 77438489 is about 8799.9141473085. The cubic root of 77438489 is about 426.2381224349.

It can be divided in two parts, 77 and 438489, that multiplied together give a triangular number (33763653 = T₈₂₁₇).

The spelling of 77438489 in words is "seventy-seven million, four hundred thirty-eight thousand, four hundred eighty-nine".