421440 has 56 divisors (see below), whose sum is σ = 1341120. Its totient is φ = 112128.

The previous prime is 421433. The next prime is 421453. The reversal of 421440 is 44124.

It is a super-2 number, since 2×421440² = 355223347200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 421440.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 741 + ... + 1179.

2⁴²¹⁴⁴⁰ is an apocalyptic number.

421440 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 421440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (670560).

421440 is an abundant number, since it is smaller than the sum of its proper divisors (919680).

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

421440 is a wasteful number, since it uses less digits than its factorization.

421440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 459 (or 449 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 15.

The square root of 421440 is about 649.1841033174. The cubic root of 421440 is about 74.9742133572.

Adding to 421440 its reverse (44124), we get a palindrome (465564).

It can be divided in two parts, 421 and 440, that added together give a triangular number (861 = T₄₁).

The spelling of 421440 in words is "four hundred twenty-one thousand, four hundred forty", and thus it is an iban number.