1287751680 has 288 divisors, whose sum is σ = 4542010200. Its totient is φ = 337379328.

The previous prime is 1287751651. The next prime is 1287751681. The reversal of 1287751680 is 861577821.

It is a happy number.

1287751680 is a `hidden beast` number, since 128 + 7 + 7 + 516 + 8 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 707134464 + 580617216 = 26592^2 + 24096^2 .

It is a tau number, because it is divible by the number of its divisors (288).

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

It is not an unprimeable number, because it can be changed into a prime (1287751681) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8202162 + ... + 8202318.

Almost surely, 2^1287751680 is an apocalyptic number.

1287751680 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 1287751680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2271005100).

1287751680 is an abundant number, since it is smaller than the sum of its proper divisors (3254258520).

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

1287751680 is a wasteful number, since it uses less digits than its factorization.

1287751680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 279 (or 256 counting only the distinct ones).

The product of its (nonzero) digits is 188160, while the sum is 45.

The square root of 1287751680 is about 35885.2571399454. The cubic root of 1287751680 is about 1087.9544386919.

The spelling of 1287751680 in words is "one billion, two hundred eighty-seven million, seven hundred fifty-one thousand, six hundred eighty".