42138321 has 4 divisors (see below), whose sum is σ = 56184432. Its totient is φ = 28092212.

The previous prime is 42138319. The next prime is 42138347. The reversal of 42138321 is 12383124.

42138321 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 42138321 - 2¹ = 42138319 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 42138291 and 42138300.

It is not an unprimeable number, because it can be changed into a prime (42138391) 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, 7023051 + ... + 7023056.

It is an arithmetic number, because the mean of its divisors is an integer number (14046108).

Almost surely, 2^42138321 is an apocalyptic number.

It is an amenable number.

42138321 is a deficient number, since it is larger than the sum of its proper divisors (14046111).

42138321 is a wasteful number, since it uses less digits than its factorization.

42138321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14046110.

The product of its digits is 1152, while the sum is 24.

The square root of 42138321 is about 6491.4036232544. The cubic root of 42138321 is about 347.9838395851.

The spelling of 42138321 in words is "forty-two million, one hundred thirty-eight thousand, three hundred twenty-one".