1289096856 has 80 divisors (see below), whose sum is σ = 3633949440. Its totient is φ = 426928320.

The previous prime is 1289096833. The next prime is 1289096873. The reversal of 1289096856 is 6586909821.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 95401 + ... + 108071.

It is an arithmetic number, because the mean of its divisors is an integer number (45424368).

Almost surely, 2^1289096856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1289096856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1816974720).

1289096856 is an abundant number, since it is smaller than the sum of its proper divisors (2344852584).

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

1289096856 is a wasteful number, since it uses less digits than its factorization.

1289096856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12846 (or 12833 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 54.

The square root of 1289096856 is about 35903.9949866307. The cubic root of 1289096856 is about 1088.3331299501. Note that the first 3 decimals are identical.

It can be divided in two parts, 12890 and 96856, that added together give a triangular number (109746 = T₄₆₈).

The spelling of 1289096856 in words is "one billion, two hundred eighty-nine million, ninety-six thousand, eight hundred fifty-six".