42540331891 has 4 divisors (see below), whose sum is σ = 42585253992. Its totient is φ = 42495409792.

The previous prime is 42540331859. The next prime is 42540331907. The reversal of 42540331891 is 19813304524.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 42540331891 - 2⁵ = 42540331859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42540331991) 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 in 3 ways as a sum of consecutive naturals, for example, 22459630 + ... + 22461523.

It is an arithmetic number, because the mean of its divisors is an integer number (10646313498).

Almost surely, 2^42540331891 is an apocalyptic number.

42540331891 is a deficient number, since it is larger than the sum of its proper divisors (44922101).

42540331891 is an equidigital number, since it uses as much as digits as its factorization.

42540331891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44922100.

The product of its (nonzero) digits is 103680, while the sum is 40.

The spelling of 42540331891 in words is "forty-two billion, five hundred forty million, three hundred thirty-one thousand, eight hundred ninety-one".