1311243516 has 72 divisors (see below), whose sum is σ = 3619918848. Its totient is φ = 396900000.

The previous prime is 1311243511. The next prime is 1311243529. The reversal of 1311243516 is 6153421131.

It is a happy number.

1311243516 is a `hidden beast` number, since 131 + 12 + 4 + 3 + 516 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 1311243516.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311243511) 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, 581391 + ... + 583641.

Almost surely, 2^1311243516 is an apocalyptic number.

It is an amenable number.

1311243516 is an abundant number, since it is smaller than the sum of its proper divisors (2308675332).

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

1311243516 is a wasteful number, since it uses less digits than its factorization.

1311243516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3743 (or 3738 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 1311243516 is about 36211.0965865437. The cubic root of 1311243516 is about 1094.5302895661.

Adding to 1311243516 its reverse (6153421131), we get a palindrome (7464664647).

The spelling of 1311243516 in words is "one billion, three hundred eleven million, two hundred forty-three thousand, five hundred sixteen".