428606640 has 400 divisors, whose sum is σ = 1858095360. Its totient is φ = 88957440.

The previous prime is 428606603. The next prime is 428606641. The reversal of 428606640 is 46606824.

It is a happy number.

428606640 is a `hidden beast` number, since 4 + 2 + 8 + 6 + 0 + 6 + 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 = 428606595 and 428606604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (428606641) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 498531 + ... + 499389.

Almost surely, 2^428606640 is an apocalyptic number.

428606640 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 428606640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (929047680).

428606640 is an abundant number, since it is smaller than the sum of its proper divisors (1429488720).

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

428606640 is a wasteful number, since it uses less digits than its factorization.

428606640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 902 (or 887 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The square root of 428606640 is about 20702.8171995987. The cubic root of 428606640 is about 753.9680886710.

The spelling of 428606640 in words is "four hundred twenty-eight million, six hundred six thousand, six hundred forty".