421003440 has 640 divisors, whose sum is σ = 1799884800. Its totient is φ = 89026560.

The previous prime is 421003423. The next prime is 421003441. The reversal of 421003440 is 44300124.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (421003441) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 8957497 + ... + 8957543.

It is an arithmetic number, because the mean of its divisors is an integer number (2812320).

Almost surely, 2^421003440 is an apocalyptic number.

421003440 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 421003440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (899942400).

421003440 is an abundant number, since it is smaller than the sum of its proper divisors (1378881360).

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

421003440 is a wasteful number, since it uses less digits than its factorization.

421003440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122 (or 110 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 421003440 is about 20518.3683561827. The cubic root of 421003440 is about 749.4831639224.

Adding to 421003440 its reverse (44300124), we get a palindrome (465303564).

The spelling of 421003440 in words is "four hundred twenty-one million, three thousand, four hundred forty".