1315505661 has 4 divisors (see below), whose sum is σ = 1754007552. Its totient is φ = 877003772.

The previous prime is 1315505657. The next prime is 1315505663. The reversal of 1315505661 is 1665055131.

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.

It is a cyclic number.

It is not a de Polignac number, because 1315505661 - 2² = 1315505657 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1315505663) 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, 219250941 + ... + 219250946.

It is an arithmetic number, because the mean of its divisors is an integer number (438501888).

Almost surely, 2^1315505661 is an apocalyptic number.

It is an amenable number.

1315505661 is a deficient number, since it is larger than the sum of its proper divisors (438501891).

1315505661 is an equidigital number, since it uses as much as digits as its factorization.

1315505661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 438501890.

The product of its (nonzero) digits is 13500, while the sum is 33.

The square root of 1315505661 is about 36269.9002066452. The cubic root of 1315505661 is about 1095.7149160512.

The spelling of 1315505661 in words is "one billion, three hundred fifteen million, five hundred five thousand, six hundred sixty-one".