42981839 has 2 divisors, whose sum is σ = 42981840. Its totient is φ = 42981838.

The previous prime is 42981833. The next prime is 42981847. The reversal of 42981839 is 93818924.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 42981839 - 2²⁰ = 41933263 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 42981839.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42981833) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21490919 + 21490920.

It is an arithmetic number, because the mean of its divisors is an integer number (21490920).

Almost surely, 2^42981839 is an apocalyptic number.

42981839 is a deficient number, since it is larger than the sum of its proper divisors (1).

42981839 is an equidigital number, since it uses as much as digits as its factorization.

42981839 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 124416, while the sum is 44.

The square root of 42981839 is about 6556.0536147899. The cubic root of 42981839 is about 350.2904772235.

The spelling of 42981839 in words is "forty-two million, nine hundred eighty-one thousand, eight hundred thirty-nine".