428624640 has 216 divisors, whose sum is σ = 1535330160. Its totient is φ = 110272512.

The previous prime is 428624579. The next prime is 428624641. The reversal of 428624640 is 46426824.

It is a happy number.

428624640 is a `hidden beast` number, since 4 + 2 + 8 + 6 + 2 + 4 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 428624595 and 428624604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (428624641) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 333439 + ... + 334721.

It is an arithmetic number, because the mean of its divisors is an integer number (7108010).

Almost surely, 2^428624640 is an apocalyptic number.

428624640 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 428624640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (767665080).

428624640 is an abundant number, since it is smaller than the sum of its proper divisors (1106705520).

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

428624640 is a wasteful number, since it uses less digits than its factorization.

428624640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1339 (or 1322 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 36.

The square root of 428624640 is about 20703.2519184789. The cubic root of 428624640 is about 753.9786432093.

The spelling of 428624640 in words is "four hundred twenty-eight million, six hundred twenty-four thousand, six hundred forty".