1287349920 has 144 divisors (see below), whose sum is σ = 4446423072. Its totient is φ = 339125760.

The previous prime is 1287349909. The next prime is 1287349937. The reversal of 1287349920 is 299437821.

1287349920 is a `hidden beast` number, since 1 + 287 + 349 + 9 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 114135 + ... + 124905.

It is an arithmetic number, because the mean of its divisors is an integer number (30877938).

Almost surely, 2^1287349920 is an apocalyptic number.

1287349920 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 1287349920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2223211536).

1287349920 is an abundant number, since it is smaller than the sum of its proper divisors (3159073152).

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

1287349920 is a wasteful number, since it uses less digits than its factorization.

1287349920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10875 (or 10864 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 1287349920 is about 35879.6588612545. The cubic root of 1287349920 is about 1087.8412848787.

The spelling of 1287349920 in words is "one billion, two hundred eighty-seven million, three hundred forty-nine thousand, nine hundred twenty".