1288721863 has 16 divisors (see below), whose sum is σ = 1562867712. Its totient is φ = 1046556000.

The previous prime is 1288721857. The next prime is 1288721899. The reversal of 1288721863 is 3681278821.

It is a cyclic number.

It is not a de Polignac number, because 1288721863 - 2²¹ = 1286624711 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1288721663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 140923 + ... + 149788.

It is an arithmetic number, because the mean of its divisors is an integer number (97679232).

Almost surely, 2^1288721863 is an apocalyptic number.

1288721863 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1288721863 is a deficient number, since it is larger than the sum of its proper divisors (274145849).

1288721863 is a wasteful number, since it uses less digits than its factorization.

1288721863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290766.

The product of its digits is 258048, while the sum is 46.

The square root of 1288721863 is about 35898.7724441937. The cubic root of 1288721863 is about 1088.2275891644.

The spelling of 1288721863 in words is "one billion, two hundred eighty-eight million, seven hundred twenty-one thousand, eight hundred sixty-three".