42420431 has 4 divisors (see below), whose sum is σ = 43788864. Its totient is φ = 41052000.

The previous prime is 42420419. The next prime is 42420439. The reversal of 42420431 is 13402424.

42420431 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42420431 is a prime.

It is a super-2 number, since 2×42420431² = 3598985932451522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42420439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 684170 + ... + 684231.

It is an arithmetic number, because the mean of its divisors is an integer number (10947216).

Almost surely, 2^42420431 is an apocalyptic number.

42420431 is a deficient number, since it is larger than the sum of its proper divisors (1368433).

42420431 is a wasteful number, since it uses less digits than its factorization.

42420431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1368432.

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

The square root of 42420431 is about 6513.0968824362. The cubic root of 42420431 is about 348.7586802565.

Adding to 42420431 its reverse (13402424), we get a palindrome (55822855).

The spelling of 42420431 in words is "forty-two million, four hundred twenty thousand, four hundred thirty-one".