420340421 has 4 divisors (see below), whose sum is σ = 420734700. Its totient is φ = 419946144.

The previous prime is 420340397. The next prime is 420340423. The reversal of 420340421 is 124043024.

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 179935396 + 240405025 = 13414^2 + 15505^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-420340421 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 420340393 and 420340402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420340423) 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, 195536 + ... + 197673.

It is an arithmetic number, because the mean of its divisors is an integer number (105183675).

Almost surely, 2^420340421 is an apocalyptic number.

It is an amenable number.

420340421 is a deficient number, since it is larger than the sum of its proper divisors (394279).

420340421 is a wasteful number, since it uses less digits than its factorization.

420340421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394278.

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

The square root of 420340421 is about 20502.2052716287. The cubic root of 420340421 is about 749.0895149885.

Adding to 420340421 its reverse (124043024), we get a palindrome (544383445).

The spelling of 420340421 in words is "four hundred twenty million, three hundred forty thousand, four hundred twenty-one".