42340421 has 4 divisors (see below), whose sum is σ = 44831052. Its totient is φ = 39849792.

The previous prime is 42340411. The next prime is 42340427. The reversal of 42340421 is 12404324.

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

It can be written as a sum of positive squares in 2 ways, for example, as 39551521 + 2788900 = 6289^2 + 1670^2 .

It is a cyclic number.

It is not a de Polignac number, because 42340421 - 2⁶ = 42340357 is a prime.

It is a super-2 number, since 2×42340421² = 3585422500914482, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 42340393 and 42340402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42340427) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1245290 + ... + 1245323.

It is an arithmetic number, because the mean of its divisors is an integer number (11207763).

Almost surely, 2^42340421 is an apocalyptic number.

It is an amenable number.

42340421 is a deficient number, since it is larger than the sum of its proper divisors (2490631).

42340421 is a wasteful number, since it uses less digits than its factorization.

42340421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2490630.

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

The square root of 42340421 is about 6506.9517440965. The cubic root of 42340421 is about 348.5392754140.

Adding to 42340421 its reverse (12404324), we get a palindrome (54744745).

The spelling of 42340421 in words is "forty-two million, three hundred forty thousand, four hundred twenty-one".