1315530521 has 4 divisors (see below), whose sum is σ = 1315626000. Its totient is φ = 1315435044.

The previous prime is 1315530511. The next prime is 1315530577. The reversal of 1315530521 is 1250355131.

It is a happy number.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1315530521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1315530511) 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, 22691 + ... + 56088.

It is an arithmetic number, because the mean of its divisors is an integer number (328906500).

Almost surely, 2^1315530521 is an apocalyptic number.

It is an amenable number.

1315530521 is a deficient number, since it is larger than the sum of its proper divisors (95479).

1315530521 is an equidigital number, since it uses as much as digits as its factorization.

1315530521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95478.

The product of its (nonzero) digits is 2250, while the sum is 26.

The square root of 1315530521 is about 36270.2429134408. The cubic root of 1315530521 is about 1095.7218181629.

Adding to 1315530521 its reverse (1250355131), we get a palindrome (2565885652).

The spelling of 1315530521 in words is "one billion, three hundred fifteen million, five hundred thirty thousand, five hundred twenty-one".