421906 has 8 divisors (see below), whose sum is σ = 670140. Its totient is φ = 198528.

The previous prime is 421891. The next prime is 421907. The reversal of 421906 is 609124.

421906 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 410881 + 11025 = 641^2 + 105^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (421907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6171 + ... + 6238.

2⁴²¹⁹⁰⁶ is an apocalyptic number.

421906 is a deficient number, since it is larger than the sum of its proper divisors (248234).

421906 is a wasteful number, since it uses less digits than its factorization.

421906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12428.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 421906 is about 649.5429162111. The cubic root of 421906 is about 75.0018369920.

The spelling of 421906 in words is "four hundred twenty-one thousand, nine hundred six".