1288745640 has 768 divisors, whose sum is σ = 5635768320. Its totient is φ = 257541120.

The previous prime is 1288745629. The next prime is 1288745641. The reversal of 1288745640 is 465478821.

1288745640 is a `hidden beast` number, since 1 + 2 + 8 + 87 + 4 + 564 + 0 = 666.

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 (1288745641) by changing a digit.

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 191 ways as a sum of consecutive naturals, for example, 27420097 + ... + 27420143.

It is an arithmetic number, because the mean of its divisors is an integer number (7338240).

Almost surely, 2^1288745640 is an apocalyptic number.

1288745640 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 1288745640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2817884160).

1288745640 is an abundant number, since it is smaller than the sum of its proper divisors (4347022680).

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

1288745640 is a wasteful number, since it uses less digits than its factorization.

1288745640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124 (or 108 counting only the distinct ones).

The product of its (nonzero) digits is 430080, while the sum is 45.

The square root of 1288745640 is about 35899.1036099789. The cubic root of 1288745640 is about 1088.2342817459.

The spelling of 1288745640 in words is "one billion, two hundred eighty-eight million, seven hundred forty-five thousand, six hundred forty".