421408 has 24 divisors (see below), whose sum is σ = 894348. Its totient is φ = 194304.

The previous prime is 421397. The next prime is 421409. The reversal of 421408 is 804124.

It can be written as a sum of positive squares in 2 ways, for example, as 300304 + 121104 = 548^2 + 348^2 .

It is a Smith number, since the sum of its digits (19) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (421409) 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, 91 + ... + 922.

2⁴²¹⁴⁰⁸ is an apocalyptic number.

It is an amenable number.

421408 is an abundant number, since it is smaller than the sum of its proper divisors (472940).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

421408 is a wasteful number, since it uses less digits than its factorization.

421408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1036 (or 1028 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 421408 is about 649.1594565282. The cubic root of 421408 is about 74.9723157082.

It can be divided in two parts, 4 and 21408, that added together give a palindrome (21412).

The spelling of 421408 in words is "four hundred twenty-one thousand, four hundred eight".