42178813 has 2 divisors, whose sum is σ = 42178814. Its totient is φ = 42178812.

The previous prime is 42178769. The next prime is 42178907. The reversal of 42178813 is 31887124.

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., 37417689 + 4761124 = 6117^2 + 2182^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42178813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42172813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21089406 + 21089407.

It is an arithmetic number, because the mean of its divisors is an integer number (21089407).

Almost surely, 2^42178813 is an apocalyptic number.

It is an amenable number.

42178813 is a deficient number, since it is larger than the sum of its proper divisors (1).

42178813 is an equidigital number, since it uses as much as digits as its factorization.

42178813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10752, while the sum is 34.

The square root of 42178813 is about 6494.5217683829. The cubic root of 42178813 is about 348.0952666690.

The spelling of 42178813 in words is "forty-two million, one hundred seventy-eight thousand, eight hundred thirteen".