1287821376 has 112 divisors (see below), whose sum is σ = 3799514880. Its totient is φ = 427737600.

The previous prime is 1287821363. The next prime is 1287821377. The reversal of 1287821376 is 6731287821.

It is not an unprimeable number, because it can be changed into a prime (1287821377) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 546601 + ... + 548951.

It is an arithmetic number, because the mean of its divisors is an integer number (33924240).

Almost surely, 2^1287821376 is an apocalyptic number.

1287821376 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 1287821376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1899757440).

1287821376 is an abundant number, since it is smaller than the sum of its proper divisors (2511693504).

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

1287821376 is a wasteful number, since it uses less digits than its factorization.

1287821376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2689 (or 2673 counting only the distinct ones).

The product of its digits is 225792, while the sum is 45.

The square root of 1287821376 is about 35886.2282219795. The cubic root of 1287821376 is about 1087.9740658466.

The spelling of 1287821376 in words is "one billion, two hundred eighty-seven million, eight hundred twenty-one thousand, three hundred seventy-six".