428228640 has 576 divisors, whose sum is σ = 1856736000. Its totient is φ = 92123136.

The previous prime is 428228629. The next prime is 428228653. The reversal of 428228640 is 46822824.

It is a happy number.

428228640 is a `hidden beast` number, since 4 + 2 + 8 + 2 + 2 + 8 + 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 = 428228595 and 428228604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 25189912 + ... + 25189928.

It is an arithmetic number, because the mean of its divisors is an integer number (3223500).

Almost surely, 2^428228640 is an apocalyptic number.

428228640 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 428228640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (928368000).

428228640 is an abundant number, since it is smaller than the sum of its proper divisors (1428507360).

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

428228640 is a wasteful number, since it uses less digits than its factorization.

428228640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79 (or 34 counting only the distinct ones).

The product of its (nonzero) digits is 49152, while the sum is 36.

The square root of 428228640 is about 20693.6859935585. The cubic root of 428228640 is about 753.7463750723.

The spelling of 428228640 in words is "four hundred twenty-eight million, two hundred twenty-eight thousand, six hundred forty".