1428256440 has 192 divisors, whose sum is σ = 5081862240. Its totient is φ = 345738240.

The previous prime is 1428256433. The next prime is 1428256441. The reversal of 1428256440 is 446528241.

1428256440 is a `hidden beast` number, since 1 + 4 + 2 + 8 + 2 + 5 + 644 + 0 = 666.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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 = 1428256395 and 1428256404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1428256441) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 282979 + ... + 287981.

Almost surely, 2^1428256440 is an apocalyptic number.

1428256440 is a gapful number since it is divisible by the number (10) 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 1428256440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2540931120).

1428256440 is an abundant number, since it is smaller than the sum of its proper divisors (3653605800).

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

1428256440 is a wasteful number, since it uses less digits than its factorization.

1428256440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5094 (or 5087 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 36.

The square root of 1428256440 is about 37792.2801640758. The cubic root of 1428256440 is about 1126.1650981431.

The spelling of 1428256440 in words is "one billion, four hundred twenty-eight million, two hundred fifty-six thousand, four hundred forty".