1286943840 has 864 divisors, whose sum is σ = 5835001536. Its totient is φ = 255467520.

The previous prime is 1286943829. The next prime is 1286943841. The reversal of 1286943840 is 483496821.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1286943841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 21097410 + ... + 21097470.

It is an arithmetic number, because the mean of its divisors is an integer number (6753474).

Almost surely, 2^1286943840 is an apocalyptic number.

1286943840 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 1286943840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2917500768).

1286943840 is an abundant number, since it is smaller than the sum of its proper divisors (4548057696).

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

1286943840 is a wasteful number, since it uses less digits than its factorization.

1286943840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132 (or 114 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 45.

The square root of 1286943840 is about 35873.9994982438. Note that the first 3 decimals coincide. The cubic root of 1286943840 is about 1087.7268904319.

The spelling of 1286943840 in words is "one billion, two hundred eighty-six million, nine hundred forty-three thousand, eight hundred forty".