42078989 has 2 divisors, whose sum is σ = 42078990. Its totient is φ = 42078988.

The previous prime is 42078929. The next prime is 42079013. The reversal of 42078989 is 98987024.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41860900 + 218089 = 6470^2 + 467^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42078989 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 (42078929) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21039494 + 21039495.

It is an arithmetic number, because the mean of its divisors is an integer number (21039495).

Almost surely, 2^42078989 is an apocalyptic number.

It is an amenable number.

42078989 is a deficient number, since it is larger than the sum of its proper divisors (1).

42078989 is an equidigital number, since it uses as much as digits as its factorization.

42078989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 290304, while the sum is 47.

The square root of 42078989 is about 6486.8319694594. The cubic root of 42078989 is about 347.8204390303.

The spelling of 42078989 in words is "forty-two million, seventy-eight thousand, nine hundred eighty-nine".