1311521 has 4 divisors (see below), whose sum is σ = 1314372. Its totient is φ = 1308672.

The previous prime is 1311509. The next prime is 1311523. The reversal of 1311521 is 1251131.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1254400 + 57121 = 1120^2 + 239^2 .

It is a cyclic number.

It is not a de Polignac number, because 1311521 - 2¹⁴ = 1295137 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1311496 and 1311505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311523) 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, 560 + ... + 1713.

It is an arithmetic number, because the mean of its divisors is an integer number (328593).

2^1311521 is an apocalyptic number.

It is an amenable number.

1311521 is a deficient number, since it is larger than the sum of its proper divisors (2851).

1311521 is an equidigital number, since it uses as much as digits as its factorization.

1311521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2850.

The product of its digits is 30, while the sum is 14.

The square root of 1311521 is about 1145.2165734043. The cubic root of 1311521 is about 109.4607491911.

Adding to 1311521 its reverse (1251131), we get a palindrome (2562652).

The spelling of 1311521 in words is "one million, three hundred eleven thousand, five hundred twenty-one".