421424640 has 640 divisors, whose sum is σ = 1869880320. Its totient is φ = 87588864.

The previous prime is 421424599. The next prime is 421424657. The reversal of 421424640 is 46424124.

It is a happy number.

421424640 is a `hidden beast` number, since 4 + 2 + 14 + 2 + 4 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6289887 + ... + 6289953.

It is an arithmetic number, because the mean of its divisors is an integer number (2921688).

Almost surely, 2^421424640 is an apocalyptic number.

421424640 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 421424640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (934940160).

421424640 is an abundant number, since it is smaller than the sum of its proper divisors (1448455680).

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

421424640 is a wasteful number, since it uses less digits than its factorization.

421424640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119 (or 97 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 27.

The square root of 421424640 is about 20528.6297643072. The cubic root of 421424640 is about 749.7330249771.

Adding to 421424640 its reverse (46424124), we get a palindrome (467848764).

The spelling of 421424640 in words is "four hundred twenty-one million, four hundred twenty-four thousand, six hundred forty".