1288408639 has 24 divisors (see below), whose sum is σ = 1604272128. Its totient is φ = 1012415760.

The previous prime is 1288408637. The next prime is 1288408651. The reversal of 1288408639 is 9368048821.

It is not a de Polignac number, because 1288408639 - 2¹ = 1288408637 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1288408592 and 1288408601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1288408637) 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, 70114 + ... + 86560.

It is an arithmetic number, because the mean of its divisors is an integer number (66844672).

Almost surely, 2^1288408639 is an apocalyptic number.

1288408639 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

1288408639 is a deficient number, since it is larger than the sum of its proper divisors (315863489).

1288408639 is a wasteful number, since it uses less digits than its factorization.

1288408639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16523 (or 16504 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 49.

The square root of 1288408639 is about 35894.4095786517. The cubic root of 1288408639 is about 1088.1394174062.

The spelling of 1288408639 in words is "one billion, two hundred eighty-eight million, four hundred eight thousand, six hundred thirty-nine".