1311551 has 4 divisors (see below), whose sum is σ = 1380600. Its totient is φ = 1242504.

The previous prime is 1311547. The next prime is 1311553. The reversal of 1311551 is 1551131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1551131 = 17 ⋅91243.

It is a cyclic number.

It is not a de Polignac number, because 1311551 - 2² = 1311547 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 (1311553) 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, 34496 + ... + 34533.

It is an arithmetic number, because the mean of its divisors is an integer number (345150).

2^1311551 is an apocalyptic number.

1311551 is a deficient number, since it is larger than the sum of its proper divisors (69049).

1311551 is an equidigital number, since it uses as much as digits as its factorization.

1311551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69048.

The product of its digits is 75, while the sum is 17.

The square root of 1311551 is about 1145.2296712887. The cubic root of 1311551 is about 109.4615837939.

Adding to 1311551 its reverse (1551131), we get a palindrome (2862682).

The spelling of 1311551 in words is "one million, three hundred eleven thousand, five hundred fifty-one".