1315543661 has 4 divisors (see below), whose sum is σ = 1318385472. Its totient is φ = 1312701852.

The previous prime is 1315543651. The next prime is 1315543681. The reversal of 1315543661 is 1663455131.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1663455131 = 13 ⋅127958087.

It is a cyclic number.

It is not a de Polignac number, because 1315543661 - 2¹⁴ = 1315527277 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 (1315543651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1420211 + ... + 1421136.

It is an arithmetic number, because the mean of its divisors is an integer number (329596368).

Almost surely, 2^1315543661 is an apocalyptic number.

It is an amenable number.

1315543661 is a deficient number, since it is larger than the sum of its proper divisors (2841811).

1315543661 is an equidigital number, since it uses as much as digits as its factorization.

1315543661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2841810.

The product of its digits is 32400, while the sum is 35.

The square root of 1315543661 is about 36270.4240532145. The cubic root of 1315543661 is about 1095.7254663075.

Adding to 1315543661 its reverse (1663455131), we get a palindrome (2978998792).

The spelling of 1315543661 in words is "one billion, three hundred fifteen million, five hundred forty-three thousand, six hundred sixty-one".