1288816720 has 20 divisors (see below), whose sum is σ = 2996499060. Its totient is φ = 515526656.

The previous prime is 1288816717. The next prime is 1288816747. The reversal of 1288816720 is 276188821.

It can be written as a sum of positive squares in 2 ways, for example, as 757790784 + 531025936 = 27528^2 + 23044^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×1288816720² = 3322097075503116800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8055025 + ... + 8055184.

It is an arithmetic number, because the mean of its divisors is an integer number (149824953).

Almost surely, 2^1288816720 is an apocalyptic number.

1288816720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1288816720 is an abundant number, since it is smaller than the sum of its proper divisors (1707682340).

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

1288816720 is a wasteful number, since it uses less digits than its factorization.

1288816720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16110222 (or 16110216 counting only the distinct ones).

The product of its (nonzero) digits is 86016, while the sum is 43.

The square root of 1288816720 is about 35900.0935931928. The cubic root of 1288816720 is about 1088.2542883498.

The spelling of 1288816720 in words is "one billion, two hundred eighty-eight million, eight hundred sixteen thousand, seven hundred twenty".