42806789 has 2 divisors, whose sum is σ = 42806790. Its totient is φ = 42806788.

The previous prime is 42806783. The next prime is 42806831. The reversal of 42806789 is 98760824.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42797764 + 9025 = 6542^2 + 95^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42806789 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42806783) 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, 21403394 + 21403395.

It is an arithmetic number, because the mean of its divisors is an integer number (21403395).

Almost surely, 2^42806789 is an apocalyptic number.

It is an amenable number.

42806789 is a deficient number, since it is larger than the sum of its proper divisors (1).

42806789 is an equidigital number, since it uses as much as digits as its factorization.

42806789 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 193536, while the sum is 44.

The square root of 42806789 is about 6542.6897374092. The cubic root of 42806789 is about 349.8142933200.

The spelling of 42806789 in words is "forty-two million, eight hundred six thousand, seven hundred eighty-nine".