421403424 has 192 divisors, whose sum is σ = 1271096064. Its totient is φ = 121245696.

The previous prime is 421403417. The next prime is 421403431. The reversal of 421403424 is 424304124.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (421403417) and next prime (421403431).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a junction number, because it is equal to n+sod(n) for n = 421403394 and 421403403.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1521174 + ... + 1521450.

It is an arithmetic number, because the mean of its divisors is an integer number (6620292).

Almost surely, 2^421403424 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 421403424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (635548032).

421403424 is an abundant number, since it is smaller than the sum of its proper divisors (849692640).

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

421403424 is a wasteful number, since it uses less digits than its factorization.

421403424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 379 (or 371 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 24.

The square root of 421403424 is about 20528.1130160568. The cubic root of 421403424 is about 749.7204433660.

Adding to 421403424 its reverse (424304124), we get a palindrome (845707548).

The spelling of 421403424 in words is "four hundred twenty-one million, four hundred three thousand, four hundred twenty-four".