42042431 has 6 divisors (see below), whose sum is σ = 43543032. Its totient is φ = 40591880.

The previous prime is 42042389. The next prime is 42042439. The reversal of 42042431 is 13424024.

It is a de Polignac number, because none of the positive numbers 2^k-42042431 is a prime.

It is a super-2 number, since 2×42042431² = 3535132008779522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42042439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 24155 + ... + 25836.

It is an arithmetic number, because the mean of its divisors is an integer number (7257172).

Almost surely, 2^42042431 is an apocalyptic number.

42042431 is a deficient number, since it is larger than the sum of its proper divisors (1500601).

42042431 is an equidigital number, since it uses as much as digits as its factorization.

42042431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50049 (or 50020 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 42042431 is about 6484.0134947423. The cubic root of 42042431 is about 347.7196816681.

Adding to 42042431 its reverse (13424024), we get a palindrome (55466455).

The spelling of 42042431 in words is "forty-two million, forty-two thousand, four hundred thirty-one".