421438 has 4 divisors (see below), whose sum is σ = 632160. Its totient is φ = 210718.

The previous prime is 421433. The next prime is 421453. The reversal of 421438 is 834124.

421438 is digitally balanced in base 3, 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 Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105358 + ... + 105361.

It is an arithmetic number, because the mean of its divisors is an integer number (158040).

2⁴²¹⁴³⁸ is an apocalyptic number.

421438 is a deficient number, since it is larger than the sum of its proper divisors (210722).

421438 is a wasteful number, since it uses less digits than its factorization.

421438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210721.

The product of its digits is 768, while the sum is 22.

The square root of 421438 is about 649.1825629205. The cubic root of 421438 is about 74.9740947570.

Subtracting 421438 from its reverse (834124), we obtain a triangular number (412686 = T₉₀₈).

The spelling of 421438 in words is "four hundred twenty-one thousand, four hundred thirty-eight".