1288985813 has 4 divisors (see below), whose sum is σ = 1294001580. Its totient is φ = 1283970048.

The previous prime is 1288985809. The next prime is 1288985833. The reversal of 1288985813 is 3185898821.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1080962884 + 208022929 = 32878^2 + 14423^2 .

It is a cyclic number.

It is not a de Polignac number, because 1288985813 - 2² = 1288985809 is a prime.

It is a super-2 number, since 2×1288985813² = 3322968852230541938, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1288985833) 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, 2507498 + ... + 2508011.

It is an arithmetic number, because the mean of its divisors is an integer number (323500395).

Almost surely, 2^1288985813 is an apocalyptic number.

It is an amenable number.

1288985813 is a deficient number, since it is larger than the sum of its proper divisors (5015767).

1288985813 is an equidigital number, since it uses as much as digits as its factorization.

1288985813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5015766.

The product of its digits is 1105920, while the sum is 53.

The square root of 1288985813 is about 35902.4485655227. The cubic root of 1288985813 is about 1088.3018793254.

The spelling of 1288985813 in words is "one billion, two hundred eighty-eight million, nine hundred eighty-five thousand, eight hundred thirteen".