1287587840 has 384 divisors, whose sum is σ = 4075868160. Its totient is φ = 378470400.

The previous prime is 1287587789. The next prime is 1287587891. The reversal of 1287587840 is 487857821.

It is an interprime number because it is at equal distance from previous prime (1287587789) and next prime (1287587891).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18135005 + ... + 18135075.

It is an arithmetic number, because the mean of its divisors is an integer number (10614240).

Almost surely, 2^1287587840 is an apocalyptic number.

1287587840 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 1287587840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2037934080).

1287587840 is an abundant number, since it is smaller than the sum of its proper divisors (2788280320).

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

1287587840 is a wasteful number, since it uses less digits than its factorization.

1287587840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139 (or 119 counting only the distinct ones).

The product of its (nonzero) digits is 1003520, while the sum is 50.

The square root of 1287587840 is about 35882.9742357013. The cubic root of 1287587840 is about 1087.9082967692.

The spelling of 1287587840 in words is "one billion, two hundred eighty-seven million, five hundred eighty-seven thousand, eight hundred forty".