42778061 has 2 divisors, whose sum is σ = 42778062. Its totient is φ = 42778060.

The previous prime is 42778051. The next prime is 42778097. The reversal of 42778061 is 16087724.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37515625 + 5262436 = 6125^2 + 2294^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42778061 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 (42778051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21389030 + 21389031.

It is an arithmetic number, because the mean of its divisors is an integer number (21389031).

Almost surely, 2^42778061 is an apocalyptic number.

It is an amenable number.

42778061 is a deficient number, since it is larger than the sum of its proper divisors (1).

42778061 is an equidigital number, since it uses as much as digits as its factorization.

42778061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18816, while the sum is 35.

The square root of 42778061 is about 6540.4939415919. The cubic root of 42778061 is about 349.7360213590.

The spelling of 42778061 in words is "forty-two million, seven hundred seventy-eight thousand, sixty-one".