78985889 has 2 divisors, whose sum is σ = 78985890. Its totient is φ = 78985888.

The previous prime is 78985817. The next prime is 78985891. The reversal of 78985889 is 98858987.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50523664 + 28462225 = 7108^2 + 5335^2 .

It is a cyclic number.

It is not a de Polignac number, because 78985889 - 2⁸ = 78985633 is a prime.

It is a super-2 number, since 2×78985889² = 12477541322240642, which contains 22 as substring.

Together with 78985891, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78985189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39492944 + 39492945.

It is an arithmetic number, because the mean of its divisors is an integer number (39492945).

Almost surely, 2^78985889 is an apocalyptic number.

It is an amenable number.

78985889 is a deficient number, since it is larger than the sum of its proper divisors (1).

78985889 is an equidigital number, since it uses as much as digits as its factorization.

78985889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11612160, while the sum is 62.

The square root of 78985889 is about 8887.4005760965. The cubic root of 78985889 is about 429.0584934812.

The spelling of 78985889 in words is "seventy-eight million, nine hundred eighty-five thousand, eight hundred eighty-nine".