1215513668 has 12 divisors (see below), whose sum is σ = 2252275452. Its totient is φ = 572006400.

The previous prime is 1215513661. The next prime is 1215513737. The reversal of 1215513668 is 8663155121.

It can be written as a sum of positive squares in 2 ways, for example, as 530749444 + 684764224 = 23038^2 + 26168^2 .

It is not an unprimeable number, because it can be changed into a prime (1215513661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8937533 + ... + 8937668.

It is an arithmetic number, because the mean of its divisors is an integer number (187689621).

Almost surely, 2^1215513668 is an apocalyptic number.

It is an amenable number.

1215513668 is a deficient number, since it is larger than the sum of its proper divisors (1036761784).

1215513668 is a wasteful number, since it uses less digits than its factorization.

1215513668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17875222 (or 17875220 counting only the distinct ones).

The product of its digits is 43200, while the sum is 38.

The square root of 1215513668 is about 34864.2175876643. The cubic root of 1215513668 is about 1067.2183456559.

Adding to 1215513668 its reverse (8663155121), we get a palindrome (9878668789).

The spelling of 1215513668 in words is "one billion, two hundred fifteen million, five hundred thirteen thousand, six hundred sixty-eight".