1287021440 has 32 divisors (see below), whose sum is σ = 3076787160. Its totient is φ = 514808320.

The previous prime is 1287021427. The next prime is 1287021497. The reversal of 1287021440 is 441207821.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 1004846 + ... + 1006125.

Almost surely, 2^1287021440 is an apocalyptic number.

1287021440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1287021440 is an abundant number, since it is smaller than the sum of its proper divisors (1789765720).

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

1287021440 is an equidigital number, since it uses as much as digits as its factorization.

1287021440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2010990 (or 2010978 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 29.

The square root of 1287021440 is about 35875.0810452046. The cubic root of 1287021440 is about 1087.7487525385.

The spelling of 1287021440 in words is "one billion, two hundred eighty-seven million, twenty-one thousand, four hundred forty".