78685489 has 2 divisors, whose sum is σ = 78685490. Its totient is φ = 78685488.

The previous prime is 78685483. The next prime is 78685493. The reversal of 78685489 is 98458687.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 73667889 + 5017600 = 8583^2 + 2240^2 .

It is a cyclic number.

It is not a de Polignac number, because 78685489 - 2⁵ = 78685457 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78685483) 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, 39342744 + 39342745.

It is an arithmetic number, because the mean of its divisors is an integer number (39342745).

Almost surely, 2^78685489 is an apocalyptic number.

It is an amenable number.

78685489 is a deficient number, since it is larger than the sum of its proper divisors (1).

78685489 is an equidigital number, since it uses as much as digits as its factorization.

78685489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3870720, while the sum is 55.

The square root of 78685489 is about 8870.4841468772. The cubic root of 78685489 is about 428.5138691322.

The spelling of 78685489 in words is "seventy-eight million, six hundred eighty-five thousand, four hundred eighty-nine".