1287794816 has 128 divisors (see below), whose sum is σ = 3219903360. Its totient is φ = 498401280.

The previous prime is 1287794797. The next prime is 1287794819. The reversal of 1287794816 is 6184977821.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

It is not an unprimeable number, because it can be changed into a prime (1287794819) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1901870 + ... + 1902546.

It is an arithmetic number, because the mean of its divisors is an integer number (25155495).

Almost surely, 2^1287794816 is an apocalyptic number.

1287794816 is a gapful number since it is divisible by the number (16) 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 1287794816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1609951680).

1287794816 is an abundant number, since it is smaller than the sum of its proper divisors (1932108544).

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

1287794816 is a wasteful number, since it uses less digits than its factorization.

1287794816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 902 (or 890 counting only the distinct ones).

The product of its digits is 1354752, while the sum is 53.

The square root of 1287794816 is about 35885.8581616770. The cubic root of 1287794816 is about 1087.9665863441.

The spelling of 1287794816 in words is "one billion, two hundred eighty-seven million, seven hundred ninety-four thousand, eight hundred sixteen".