1288243988 has 12 divisors (see below), whose sum is σ = 2254998900. Its totient is φ = 643958592.

The previous prime is 1288243987. The next prime is 1288243993. The reversal of 1288243988 is 8893428821.

It can be written as a sum of positive squares in 2 ways, for example, as 73582084 + 1214661904 = 8578^2 + 34852^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1288243987) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22163 + ... + 55386.

It is an arithmetic number, because the mean of its divisors is an integer number (187916575).

Almost surely, 2^1288243988 is an apocalyptic number.

It is an amenable number.

1288243988 is a deficient number, since it is larger than the sum of its proper divisors (966754912).

1288243988 is a wasteful number, since it uses less digits than its factorization.

1288243988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81706 (or 81704 counting only the distinct ones).

The product of its digits is 1769472, while the sum is 53.

The square root of 1288243988 is about 35892.1159588008. The cubic root of 1288243988 is about 1088.0930628387.

The spelling of 1288243988 in words is "one billion, two hundred eighty-eight million, two hundred forty-three thousand, nine hundred eighty-eight".