1287449856 has 576 divisors, whose sum is σ = 4944844800. Its totient is φ = 320716800.

The previous prime is 1287449851. The next prime is 1287449857. The reversal of 1287449856 is 6589447821.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (576).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1287449851) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 21821155 + ... + 21821213.

It is an arithmetic number, because the mean of its divisors is an integer number (8584800).

Almost surely, 2^1287449856 is an apocalyptic number.

1287449856 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 1287449856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2472422400).

1287449856 is an abundant number, since it is smaller than the sum of its proper divisors (3657394944).

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

1287449856 is a wasteful number, since it uses less digits than its factorization.

1287449856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143 (or 123 counting only the distinct ones).

The product of its digits is 3870720, while the sum is 54.

The square root of 1287449856 is about 35881.0514896094. The cubic root of 1287449856 is about 1087.8694335822.

The spelling of 1287449856 in words is "one billion, two hundred eighty-seven million, four hundred forty-nine thousand, eight hundred fifty-six".