42091789939 has 2 divisors, whose sum is σ = 42091789940. Its totient is φ = 42091789938.

The previous prime is 42091789937. The next prime is 42091789951. The reversal of 42091789939 is 93998719024.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 42091789939 - 2¹ = 42091789937 is a prime.

Together with 42091789937, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (42091789937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21045894969 + 21045894970.

It is an arithmetic number, because the mean of its divisors is an integer number (21045894970).

Almost surely, 2^42091789939 is an apocalyptic number.

42091789939 is a deficient number, since it is larger than the sum of its proper divisors (1).

42091789939 is an equidigital number, since it uses as much as digits as its factorization.

42091789939 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8817984, while the sum is 61.

The spelling of 42091789939 in words is "forty-two billion, ninety-one million, seven hundred eighty-nine thousand, nine hundred thirty-nine".