78989 has 2 divisors, whose sum is σ = 78990. Its totient is φ = 78988.

The previous prime is 78979. The next prime is 79031. The reversal of 78989 is 98987.

78989 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 75625 + 3364 = 275^2 + 58^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78989 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39494 + 39495.

It is an arithmetic number, because the mean of its divisors is an integer number (39495).

2⁷⁸⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

78989 is a deficient number, since it is larger than the sum of its proper divisors (1).

78989 is an equidigital number, since it uses as much as digits as its factorization.

78989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36288, while the sum is 41.

The square root of 78989 is about 281.0498176480. The cubic root of 78989 is about 42.9064126485.

It can be divided in two parts, 789 and 89, that added together give a palindrome (878).

The spelling of 78989 in words is "seventy-eight thousand, nine hundred eighty-nine".